From 08026a3cdc1f336fdf4e5b45b3425e3205873916 Mon Sep 17 00:00:00 2001 From: algorithmzuo Date: Thu, 28 Jul 2022 14:26:25 +0800 Subject: [PATCH] modify code --- .../Code01_WaysWiggle.java | 68 +++++++- .../Code02_MatchsticksToSquare.java | 155 ++++++++++++++++++ .../Code02_SidingPuzzle1.java | 103 ------------ .../Code02_SidingPuzzle2.java | 120 -------------- .../Code03_TheNumberOfGoodSubsets.java | 49 +++++- .../Code04_MatchsticksToSquare.java | 40 ----- ...养的大厂算法面试题(正在直播) | 33 +++- 7 files changed, 286 insertions(+), 282 deletions(-) create mode 100644 算法周更班/class_2022_07_4_week/Code02_MatchsticksToSquare.java delete mode 100644 算法周更班/class_2022_07_4_week/Code02_SidingPuzzle1.java delete mode 100644 算法周更班/class_2022_07_4_week/Code02_SidingPuzzle2.java delete mode 100644 算法周更班/class_2022_07_4_week/Code04_MatchsticksToSquare.java diff --git a/算法周更班/class_2022_07_4_week/Code01_WaysWiggle.java b/算法周更班/class_2022_07_4_week/Code01_WaysWiggle.java index 2eb13bf..8d3c470 100644 --- a/算法周更班/class_2022_07_4_week/Code01_WaysWiggle.java +++ b/算法周更班/class_2022_07_4_week/Code01_WaysWiggle.java @@ -15,6 +15,43 @@ package class_2022_07_4_week; // 因为达成不了要求 public class Code01_WaysWiggle { +// public static int ways(int[] arr) { +// // 是否天然 +// +// int n = arr.length; +// // leftUp[i] i从右往左看，能不能先升再降连到开头 +// boolean[] leftUp = new boolean[n]; +// boolean[] leftDown = new boolean[n]; +// boolean[] rightUp = new boolean[n]; +// boolean[] rightDown = new boolean[n]; +// +// // 欠缺生成的过程！ +// +// // i == 0 [0] X +// int ans = rightUp[1] || rightDown[1] ? 1 : 0; +// // i == n-1 [n-1] X +// ans += leftUp[n - 2] || leftDown[n - 2] ? 1 : 0; +// for (int i = 1; i < n - 1; i++) { +// int left = i - 1; +// int right = i + 1; +// if (arr[left] == arr[right]) { +// continue; +// } +// // 7 X 3 +// if (arr[left] > arr[right]) { +// if (rightUp[right] && leftDown[left]) { +// ans++; +// } +// } else { +// // 3 x 7 +// if (rightDown[right] && leftUp[left]) { +// ans++; +// } +// } +// } +// return ans; +// } + // 暴力方法 // 为了验证 public static int ways1(int[] arr) { @@ -91,27 +128,40 @@ public class Code01_WaysWiggle { return 0; } int n = arr.length; - boolean[] up = new boolean[n]; - boolean[] down = new boolean[n]; - up[n - 1] = true; - down[n - 1] = true; + boolean[] rightUp = new boolean[n]; + boolean[] rightDown = new boolean[n]; + rightUp[n - 1] = true; + rightDown[n - 1] = true; for (int i = n - 2; i >= 0; i--) { - up[i] = arr[i] < arr[i + 1] && down[i + 1]; - down[i] = arr[i] > arr[i + 1] && up[i + 1]; + rightUp[i] = arr[i] < arr[i + 1] && rightDown[i + 1]; + rightDown[i] = arr[i] > arr[i + 1] && rightUp[i + 1]; } - if (up[0] || down[0]) { + // 数组是不是天然符合！ + if (rightUp[0] || rightDown[0]) { return 0; } - int ans = (up[1] || down[1]) ? 1 : 0; + // 删掉0位置的数，数组达标还是不达标！ + // 1 升 + // 1 降 + int ans = (rightUp[1] || rightDown[1]) ? 1 : 0; + // ...[0] boolean leftUp = true; boolean leftDown = true; boolean tmp; for (int i = 1, l = 0, r = 2; i < n - 1; i++, l++, r++) { - ans += (arr[l] > arr[r] && up[r] && leftDown) || (arr[l] < arr[r] && down[r] && leftUp) ? 1 : 0; + ans += (arr[l] > arr[r] && rightUp[r] && leftDown) || (arr[l] < arr[r] && rightDown[r] && leftUp) ? 1 : 0; + // i（两个信息） i+1 + // 变量复用 +// boolean curLeftUp = arr[l] > arr[i] && leftDown; +// boolean curLeftDown = arr[l] < arr[i] && leftUp; +// leftUp = curLeftUp; +// leftDown = curLeftDown; tmp = leftUp; + // 7 4 leftUp = arr[l] > arr[i] && leftDown; leftDown = arr[l] < arr[i] && tmp; } + // 单独算一下 删掉n-1位置数的时候 ans += leftUp || leftDown ? 1 : 0; return ans == 0 ? -1 : ans; } diff --git a/算法周更班/class_2022_07_4_week/Code02_MatchsticksToSquare.java b/算法周更班/class_2022_07_4_week/Code02_MatchsticksToSquare.java new file mode 100644 index 0000000..3cf92e6 --- /dev/null +++ b/算法周更班/class_2022_07_4_week/Code02_MatchsticksToSquare.java @@ -0,0 +1,155 @@ +package class_2022_07_4_week; + +// 你将得到一个整数数组 matchsticks ，其中 matchsticks[i] 是第 i 个火柴棒的长度。 +// 你要用 所有的火柴棍 拼成一个正方形。 +// 你 不能折断 任何一根火柴棒，但你可以把它们连在一起，而且每根火柴棒必须 使用一次 。 +// 如果你能拼出正方形，则返回 true ，否则返回 false 。 +// 测试链接 : https://leetcode.cn/problems/matchsticks-to-square/ +public class Code02_MatchsticksToSquare { + + // 利用数组里的火柴，必须都使用 + // 能不能拼出正方形 + public static boolean yesOrNo(int[] arr) { + long sum = 0; + for (int num : arr) { + sum += num; + } + if (sum % 4 != 0) { + return false; + } + long len = sum / 4; + // 最多15根 + // 00000000000.....000000000000000 + return process(arr, 0, 0, len, 4); + } + + // 所有火柴都在arr里 + // 哪些火柴用了、哪些火柴没用，的状态都在status里 + // sum: 当前耕耘的这条边，长度已经达成了sum + // len: 固定参数，每条边必须都达成这个长度 + // edges: 还剩几条边，没填完 + // 返回：最终能不能达成正方形的目标 + // 看似，三个可变参数status, sum, edges + // 其实，只有一个，status + // 15位状态，2^15 -> 32... + public static boolean process(int[] arr, int status, long sum, long len, int edges) { + if (edges == 0) { + return status == (1 << arr.length) - 1 ? true : false; + } + // 剩下边 edges > 0 + boolean ans = false; + for (int i = 0; i < arr.length; i++) { // 当前可以选择的边，全试一遍！ + // 当前的i就是火柴编号！ + if ((status & (1 << i)) == 0) { + if (sum + arr[i] <= len) { + // 当前的边已经耕耘长度sum + 当前边的长度 不能超过len！ + if (sum + arr[i] < len) { + ans = process(arr, status | (1 << i), sum + arr[i], len, edges); + } else { // sum + arr[i] == len + ans = process(arr, status | (1 << i), 0, len, edges - 1); + } + } + } + if (ans) { + break; + } + } + return ans; + } + + // 利用数组里的火柴，必须都使用 + // 能不能拼出正方形 + public static boolean yesOrNo2(int[] arr) { + long sum = 0; + for (int num : arr) { + sum += num; + } + if (sum % 4 != 0) { + return false; + } + long len = sum / 4; + // dp[status] = + int[] dp = new int[1 << arr.length]; + // dp[status] == 0 没算过！ + // dp[status] == 1 算过，结果是true + // dp[status] == -1 算过，结果是false + + return process2(arr, 0, 0, len, 4, dp); + } + + // 所有火柴都在arr里 + // 哪些火柴用了、哪些火柴没用，的状态都在status里 + // sum: 当前耕耘的这条边，长度已经达成了sum + // len: 固定参数，每条边必须都达成这个长度 + // edges: 还剩几条边，没填完 + // 返回：最终能不能达成正方形的目标 + // 看似，三个可变参数status, sum, edges + // 其实，只有一个，status + // 15位状态，2^15 -> 32... + public static boolean process2(int[] arr, int status, long sum, long len, int edges, int[] dp) { + if (edges == 0) { + return status == (1 << arr.length) - 1 ? true : false; + } + // 缓存命中 + if (dp[status] != 0) { + return dp[status] == 1; + } + // 剩下边 edges > 0 + boolean ans = false; + for (int i = 0; i < arr.length; i++) { // 当前可以选择的边，全试一遍！ + // 当前的i就是火柴编号！ + if ((status & (1 << i)) == 0) { + if (sum + arr[i] <= len) { + // 当前的边已经耕耘长度sum + 当前边的长度 不能超过len！ + if (sum + arr[i] < len) { + ans = process2(arr, status | (1 << i), sum + arr[i], len, edges, dp); + } else { // sum + arr[i] == len + ans = process2(arr, status | (1 << i), 0, len, edges - 1, dp); + } + } + } + if (ans) { + break; + } + } + // ans == true dp[status] = 1 + // ans == false dp[status] = -1 + dp[status] = ans ? 1 : -1; + return ans; + } + + public static boolean makesquare(int[] matchsticks) { + int sum = 0; + for (int num : matchsticks) { + sum += num; + } + if ((sum & 3) != 0) { + return false; + } + int[] dp = new int[1 << matchsticks.length]; + return process(matchsticks, 0, 0, sum >> 2, 4, dp); + } + + public static boolean process(int[] arr, int status, int cur, int len, int edges, int[] dp) { + if (dp[status] != 0) { + return dp[status] == 1; + } + boolean ans = false; + if (edges == 0) { + ans = (status == (1 << arr.length) - 1) ? true : false; + } else { + for (int i = 0; i < arr.length && !ans; i++) { + if (((1 << i) & status) == 0 && cur + arr[i] <= len) { + if (cur + arr[i] == len) { + ans |= process(arr, status | (1 << i), 0, len, edges - 1, dp); + } else { + ans |= process(arr, status | (1 << i), cur + arr[i], len, edges, dp); + } + } + } + } + dp[status] = ans ? 1 : -1; + return ans; + } + +} diff --git a/算法周更班/class_2022_07_4_week/Code02_SidingPuzzle1.java b/算法周更班/class_2022_07_4_week/Code02_SidingPuzzle1.java deleted file mode 100644 index 6399d6a..0000000 --- a/算法周更班/class_2022_07_4_week/Code02_SidingPuzzle1.java +++ /dev/null @@ -1,103 +0,0 @@ -package class_2022_07_4_week; - -import java.util.HashSet; -import java.util.PriorityQueue; - -// 在一个 2 * 3 的板上（board）有 5 块砖瓦，用数字 1~5 来表示, -// 以及一块空缺用 0 来表示。一次 移动 定义为选择 0 与一个相邻的数字（上下左右）进行交换. -// 最终当板 board 的结果是 [[1,2,3],[4,5,0]] 谜板被解开。 -// 给出一个谜板的初始状态 board ， -// 返回最少可以通过多少次移动解开谜板，如果不能解开谜板，则返回 -1 。 -// 测试链接 : https://leetcode.cn/problems/sliding-puzzle/ -public class Code02_SidingPuzzle1 { - - public static int b6 = 100000; - - public static int b5 = 10000; - - public static int b4 = 1000; - - public static int b3 = 100; - - public static int b2 = 10; - - public static int[] nexts = new int[3]; - - public static int[][] end = { { 1, 2 }, { 0, 0 }, { 0, 1 }, { 0, 2 }, { 1, 0 }, { 1, 1 } }; - - public static int slidingPuzzle(int[][] m) { - HashSet set = new HashSet<>(); - int from = m[0][0] * b6 + m[0][1] * b5 + m[0][2] * b4 + m[1][0] * b3 + m[1][1] * b2 + m[1][2]; - PriorityQueue heap = new PriorityQueue<>((a, b) -> (a[0] + a[1]) - (b[0] + b[1])); - heap.add(new int[] { 0, distance(from), from }); - int ans = -1; - while (!heap.isEmpty()) { - int[] arr = heap.poll(); - int distance = arr[0]; - int cur = arr[2]; - if (set.contains(cur)) { - continue; - } - if (cur == 123450) { - ans = distance; - break; - } - set.add(cur); - int nextSize = nexts(cur); - for (int i = 0; i < nextSize; i++) { - int next = nexts[i]; - if (!set.contains(next)) { - heap.add(new int[] { distance + 1, distance(next), next }); - } - } - } - return ans; - } - - public static int nexts(int from) { - int a = from / b6; - int b = (from / b5) % 10; - int c = (from / b4) % 10; - int d = (from / b3) % 10; - int e = (from / b2) % 10; - int f = from % 10; - if (a == 0) { - nexts[0] = from + (b - a) * b6 + (a - b) * b5; - nexts[1] = from + (d - a) * b6 + (a - d) * b3; - return 2; - } else if (b == 0) { - nexts[0] = from + (a - b) * b5 + (b - a) * b6; - nexts[1] = from + (c - b) * b5 + (b - c) * b4; - nexts[2] = from + (e - b) * b5 + (b - e) * b2; - return 3; - } else if (c == 0) { - nexts[0] = from + (b - c) * b4 + (c - b) * b5; - nexts[1] = from + (f - c) * b4 + (c - f); - return 2; - } else if (d == 0) { - nexts[0] = from + (a - d) * b3 + (d - a) * b6; - nexts[1] = from + (e - d) * b3 + (d - e) * b2; - return 2; - } else if (e == 0) { - nexts[0] = from + (b - e) * b2 + (e - b) * b5; - nexts[1] = from + (d - e) * b2 + (e - d) * b3; - nexts[2] = from + (f - e) * b2 + (e - f); - return 3; - } else { - nexts[0] = from + (e - f) + (f - e) * b2; - nexts[1] = from + (c - f) + (f - c) * b4; - return 2; - } - } - - public static int distance(int num) { - int ans = end[num / b6][0] + end[num / b6][1]; - ans += end[(num / b5) % 10][0] + Math.abs(end[(num / b5) % 10][1] - 1); - ans += end[(num / b4) % 10][0] + Math.abs(end[(num / b4) % 10][1] - 2); - ans += Math.abs(end[(num / b3) % 10][0] - 1) + end[(num / b3) % 10][1]; - ans += Math.abs(end[(num / b2) % 10][0] - 1) + Math.abs(end[(num / b2) % 10][1] - 1); - ans += Math.abs(end[num % 10][0] - 1) + Math.abs(end[num % 10][1] - 2); - return ans; - } - -} diff --git a/算法周更班/class_2022_07_4_week/Code02_SidingPuzzle2.java b/算法周更班/class_2022_07_4_week/Code02_SidingPuzzle2.java deleted file mode 100644 index 5f3fdab..0000000 --- a/算法周更班/class_2022_07_4_week/Code02_SidingPuzzle2.java +++ /dev/null @@ -1,120 +0,0 @@ -package class_2022_07_4_week; - -// 在一个 2 * 3 的板上（board）有 5 块砖瓦，用数字 1~5 来表示, -// 以及一块空缺用 0 来表示。一次 移动 定义为选择 0 与一个相邻的数字（上下左右）进行交换. -// 最终当板 board 的结果是 [[1,2,3],[4,5,0]] 谜板被解开。 -// 给出一个谜板的初始状态 board ， -// 返回最少可以通过多少次移动解开谜板，如果不能解开谜板，则返回 -1 。 -// 测试链接 : https://leetcode.cn/problems/sliding-puzzle/ -public class Code02_SidingPuzzle2 { - - public static int[] status = { 12345, 12354, 12435, 12453, 12534, 12543, 13245, 13254, 13425, 13452, 13524, 13542, - 14235, 14253, 14325, 14352, 14523, 14532, 15234, 15243, 15324, 15342, 15423, 15432, 21345, 21354, 21435, - 21453, 21534, 21543, 23145, 23154, 23415, 23451, 23514, 23541, 24135, 24153, 24315, 24351, 24513, 24531, - 25134, 25143, 25314, 25341, 25413, 25431, 31245, 31254, 31425, 31452, 31524, 31542, 32145, 32154, 32415, - 32451, 32514, 32541, 34125, 34152, 34215, 34251, 34512, 34521, 35124, 35142, 35214, 35241, 35412, 35421, - 41235, 41253, 41325, 41352, 41523, 41532, 42135, 42153, 42315, 42351, 42513, 42531, 43125, 43152, 43215, - 43251, 43512, 43521, 45123, 45132, 45213, 45231, 45312, 45321, 51234, 51243, 51324, 51342, 51423, 51432, - 52134, 52143, 52314, 52341, 52413, 52431, 53124, 53142, 53214, 53241, 53412, 53421, 54123, 54132, 54213, - 54231, 54312, 54321, 102345, 102354, 102435, 102453, 102534, 102543, 103245, 103254, 103425, 103452, 103524, - 103542, 104235, 104253, 104325, 104352, 104523, 104532, 105234, 105243, 105324, 105342, 105423, 105432, - 120345, 120354, 120435, 120453, 120534, 120543, 123045, 123054, 123405, 123450, 123504, 123540, 124035, - 124053, 124305, 124350, 124503, 124530, 125034, 125043, 125304, 125340, 125403, 125430, 130245, 130254, - 130425, 130452, 130524, 130542, 132045, 132054, 132405, 132450, 132504, 132540, 134025, 134052, 134205, - 134250, 134502, 134520, 135024, 135042, 135204, 135240, 135402, 135420, 140235, 140253, 140325, 140352, - 140523, 140532, 142035, 142053, 142305, 142350, 142503, 142530, 143025, 143052, 143205, 143250, 143502, - 143520, 145023, 145032, 145203, 145230, 145302, 145320, 150234, 150243, 150324, 150342, 150423, 150432, - 152034, 152043, 152304, 152340, 152403, 152430, 153024, 153042, 153204, 153240, 153402, 153420, 154023, - 154032, 154203, 154230, 154302, 154320, 201345, 201354, 201435, 201453, 201534, 201543, 203145, 203154, - 203415, 203451, 203514, 203541, 204135, 204153, 204315, 204351, 204513, 204531, 205134, 205143, 205314, - 205341, 205413, 205431, 210345, 210354, 210435, 210453, 210534, 210543, 213045, 213054, 213405, 213450, - 213504, 213540, 214035, 214053, 214305, 214350, 214503, 214530, 215034, 215043, 215304, 215340, 215403, - 215430, 230145, 230154, 230415, 230451, 230514, 230541, 231045, 231054, 231405, 231450, 231504, 231540, - 234015, 234051, 234105, 234150, 234501, 234510, 235014, 235041, 235104, 235140, 235401, 235410, 240135, - 240153, 240315, 240351, 240513, 240531, 241035, 241053, 241305, 241350, 241503, 241530, 243015, 243051, - 243105, 243150, 243501, 243510, 245013, 245031, 245103, 245130, 245301, 245310, 250134, 250143, 250314, - 250341, 250413, 250431, 251034, 251043, 251304, 251340, 251403, 251430, 253014, 253041, 253104, 253140, - 253401, 253410, 254013, 254031, 254103, 254130, 254301, 254310, 301245, 301254, 301425, 301452, 301524, - 301542, 302145, 302154, 302415, 302451, 302514, 302541, 304125, 304152, 304215, 304251, 304512, 304521, - 305124, 305142, 305214, 305241, 305412, 305421, 310245, 310254, 310425, 310452, 310524, 310542, 312045, - 312054, 312405, 312450, 312504, 312540, 314025, 314052, 314205, 314250, 314502, 314520, 315024, 315042, - 315204, 315240, 315402, 315420, 320145, 320154, 320415, 320451, 320514, 320541, 321045, 321054, 321405, - 321450, 321504, 321540, 324015, 324051, 324105, 324150, 324501, 324510, 325014, 325041, 325104, 325140, - 325401, 325410, 340125, 340152, 340215, 340251, 340512, 340521, 341025, 341052, 341205, 341250, 341502, - 341520, 342015, 342051, 342105, 342150, 342501, 342510, 345012, 345021, 345102, 345120, 345201, 345210, - 350124, 350142, 350214, 350241, 350412, 350421, 351024, 351042, 351204, 351240, 351402, 351420, 352014, - 352041, 352104, 352140, 352401, 352410, 354012, 354021, 354102, 354120, 354201, 354210, 401235, 401253, - 401325, 401352, 401523, 401532, 402135, 402153, 402315, 402351, 402513, 402531, 403125, 403152, 403215, - 403251, 403512, 403521, 405123, 405132, 405213, 405231, 405312, 405321, 410235, 410253, 410325, 410352, - 410523, 410532, 412035, 412053, 412305, 412350, 412503, 412530, 413025, 413052, 413205, 413250, 413502, - 413520, 415023, 415032, 415203, 415230, 415302, 415320, 420135, 420153, 420315, 420351, 420513, 420531, - 421035, 421053, 421305, 421350, 421503, 421530, 423015, 423051, 423105, 423150, 423501, 423510, 425013, - 425031, 425103, 425130, 425301, 425310, 430125, 430152, 430215, 430251, 430512, 430521, 431025, 431052, - 431205, 431250, 431502, 431520, 432015, 432051, 432105, 432150, 432501, 432510, 435012, 435021, 435102, - 435120, 435201, 435210, 450123, 450132, 450213, 450231, 450312, 450321, 451023, 451032, 451203, 451230, - 451302, 451320, 452013, 452031, 452103, 452130, 452301, 452310, 453012, 453021, 453102, 453120, 453201, - 453210, 501234, 501243, 501324, 501342, 501423, 501432, 502134, 502143, 502314, 502341, 502413, 502431, - 503124, 503142, 503214, 503241, 503412, 503421, 504123, 504132, 504213, 504231, 504312, 504321, 510234, - 510243, 510324, 510342, 510423, 510432, 512034, 512043, 512304, 512340, 512403, 512430, 513024, 513042, - 513204, 513240, 513402, 513420, 514023, 514032, 514203, 514230, 514302, 514320, 520134, 520143, 520314, - 520341, 520413, 520431, 521034, 521043, 521304, 521340, 521403, 521430, 523014, 523041, 523104, 523140, - 523401, 523410, 524013, 524031, 524103, 524130, 524301, 524310, 530124, 530142, 530214, 530241, 530412, - 530421, 531024, 531042, 531204, 531240, 531402, 531420, 532014, 532041, 532104, 532140, 532401, 532410, - 534012, 534021, 534102, 534120, 534201, 534210, 540123, 540132, 540213, 540231, 540312, 540321, 541023, - 541032, 541203, 541230, 541302, 541320, 542013, 542031, 542103, 542130, 542301, 542310, 543012, 543021, - 543102, 543120, 543201, 543210 }; - - public static int[] ans = { 15, -1, -1, 3, 15, -1, -1, 15, 3, -1, -1, 17, 17, -1, -1, 15, 13, -1, -1, 17, 13, -1, - -1, 7, -1, 21, 15, -1, -1, 13, 3, -1, -1, 11, 11, -1, -1, 9, 15, -1, -1, 15, 9, -1, -1, 15, 17, -1, 15, -1, - -1, 11, 19, -1, -1, 13, 17, -1, -1, 19, 13, -1, -1, 15, 13, -1, -1, 7, 9, -1, -1, 11, -1, 9, 13, -1, -1, 9, - 17, -1, -1, 15, 7, -1, -1, 17, 7, -1, -1, 11, 19, -1, -1, 11, 11, -1, 17, -1, -1, 13, 11, -1, -1, 5, 13, -1, - -1, 15, 11, -1, -1, 15, 17, -1, -1, 11, 11, -1, -1, 15, 14, -1, -1, 2, 14, -1, -1, 14, 2, -1, -1, 16, 16, - -1, -1, 14, 12, -1, -1, 16, 12, -1, -1, 6, 13, -1, -1, 1, 13, -1, 2, -1, 1, 0, -1, -1, -1, 10, -1, -1, 11, - 12, 10, -1, 11, 12, -1, -1, -1, 15, 3, -1, -1, 17, -1, 14, -1, -1, 15, 16, 14, -1, 15, 16, -1, -1, -1, 6, - -1, -1, 5, 4, 17, -1, -1, 15, 13, -1, 16, -1, 15, 16, -1, -1, -1, 16, -1, -1, 15, 14, 18, -1, 17, 18, -1, - -1, -1, 15, 13, -1, -1, 5, -1, 4, -1, -1, 3, 4, 12, -1, 13, 14, -1, -1, -1, 12, -1, -1, 13, 14, -1, 20, 16, - -1, -1, 12, 4, -1, -1, 12, 12, -1, -1, 8, 16, -1, -1, 14, 8, -1, -1, 16, 16, -1, -1, 19, 17, -1, -1, 13, -1, - 14, -1, -1, 13, 14, 18, -1, 17, 18, -1, -1, -1, 18, -1, -1, 17, 18, 5, -1, -1, 13, 13, -1, 16, -1, 15, 14, - -1, -1, -1, 16, -1, -1, 15, 14, 8, -1, 7, 6, -1, -1, -1, 7, 15, -1, -1, 13, -1, 10, -1, -1, 11, 12, 6, -1, - 5, 6, -1, -1, -1, 12, -1, -1, 13, 14, 9, -1, -1, 15, 15, -1, 18, -1, 19, 16, -1, -1, -1, 14, -1, -1, 13, 14, - 10, -1, 9, 10, -1, -1, 14, -1, -1, 12, 18, -1, -1, 12, 16, -1, -1, 18, 12, -1, -1, 14, 14, -1, -1, 8, 10, - -1, -1, 12, 13, -1, -1, 13, 17, -1, 16, -1, 15, 14, -1, -1, -1, 16, -1, -1, 15, 16, 12, -1, 11, 12, -1, -1, - -1, 13, 15, -1, -1, 19, -1, 20, -1, -1, 19, 20, 14, -1, 13, 14, -1, -1, -1, 14, -1, -1, 13, 14, 11, -1, -1, - 15, 15, -1, 14, -1, 15, 16, -1, -1, -1, 16, -1, -1, 17, 16, 10, -1, 9, 10, -1, -1, -1, 9, 11, -1, -1, 13, - -1, 14, -1, -1, 13, 14, 12, -1, 11, 10, -1, -1, -1, 14, -1, -1, 13, 12, -1, 8, 12, -1, -1, 8, 18, -1, -1, - 14, 6, -1, -1, 18, 6, -1, -1, 10, 20, -1, -1, 10, 10, -1, -1, 7, 11, -1, -1, 7, -1, 4, -1, -1, 5, 6, 4, -1, - 5, 6, -1, -1, -1, 8, -1, -1, 9, 10, 19, -1, -1, 15, 7, -1, 14, -1, 13, 14, -1, -1, -1, 10, -1, -1, 9, 8, 18, - -1, 19, 20, -1, -1, -1, 19, 7, -1, -1, 11, -1, 10, -1, -1, 9, 10, 18, -1, 19, 20, -1, -1, -1, 10, -1, -1, 9, - 8, 21, -1, -1, 11, 11, -1, 10, -1, 9, 10, -1, -1, -1, 14, -1, -1, 13, 12, 18, -1, 19, 20, -1, -1, 16, -1, - -1, 12, 12, -1, -1, 6, 14, -1, -1, 16, 10, -1, -1, 14, 16, -1, -1, 10, 12, -1, -1, 14, 15, -1, -1, 13, 13, - -1, 16, -1, 15, 14, -1, -1, -1, 16, -1, -1, 15, 14, 14, -1, 13, 14, -1, -1, -1, 7, 15, -1, -1, 15, -1, 14, - -1, -1, 13, 14, 10, -1, 9, 8, -1, -1, -1, 16, -1, -1, 15, 16, 11, -1, -1, 15, 17, -1, 18, -1, 17, 18, -1, - -1, -1, 18, -1, -1, 17, 18, 12, -1, 11, 12, -1, -1, -1, 9, 13, -1, -1, 13, -1, 10, -1, -1, 11, 12, 8, -1, 7, - 8, -1, -1, -1, 12, -1, -1, 13, 14 }; - - public static int slidingPuzzle(int[][] board) { - int from = board[0][0] * 100000 + board[0][1] * 10000 + board[0][2] * 1000 + board[1][0] * 100 - + board[1][1] * 10 + board[1][2]; - return ans[find(from)]; - } - - public static int find(int num) { - int ans = 0; - int l = 0; - int r = status.length - 1; - int m = 0; - while (l <= r) { - m = (l + r) / 2; - if (status[m] == num) { - ans = m; - break; - } else if (status[m] > num) { - r = m - 1; - } else { - l = m + 1; - } - } - return ans; - } - -} diff --git a/算法周更班/class_2022_07_4_week/Code03_TheNumberOfGoodSubsets.java b/算法周更班/class_2022_07_4_week/Code03_TheNumberOfGoodSubsets.java index 9ab791b..79a3a06 100644 --- a/算法周更班/class_2022_07_4_week/Code03_TheNumberOfGoodSubsets.java +++ b/算法周更班/class_2022_07_4_week/Code03_TheNumberOfGoodSubsets.java @@ -2,15 +2,39 @@ package class_2022_07_4_week; import java.util.Arrays; +// 给你一个整数数组 nums 。如果 nums 的一个子集中， +// 所有元素的乘积可以表示为一个或多个 互不相同的质数 的乘积，那么我们称它为 好子集 。 +// 比方说，如果 nums = [1, 2, 3, 4] ： +// [2, 3] ，[1, 2, 3] 和 [1, 3] 是 好 子集，乘积分别为 6 = 2*3 ，6 = 2*3 和 3 = 3 。 +// [1, 4] 和 [4] 不是 好 子集，因为乘积分别为 4 = 2*2 和 4 = 2*2 。 +// 请你返回 nums 中不同的 好 子集的数目对 109 + 7 取余 的结果。 +// nums 中的 子集 是通过删除 nums 中一些（可能一个都不删除，也可能全部都删除） +// 元素后剩余元素组成的数组。 +// 如果两个子集删除的下标不同，那么它们被视为不同的子集。 // 测试链接 : https://leetcode.cn/problems/the-number-of-good-subsets/ public class Code03_TheNumberOfGoodSubsets { // 2, 3, 5, 6, 7, 10, 11, 13, 14, // 15, 17, 19, 21, 22, 23, 26, 29, 30 - public static int[] primes = { - 0, 0, 1, 2, 0, 4, 3, 8, 0, 0, - 5, 16, 0, 32, 9, 6, 0, 64, 0, 128, - 0, 10, 17, 256, 0, 0, 33, 0, 0, 512, 7 }; + public static int[] primes = { + // 11 7 5 3 2 + // 2 0 0 0 0 1 + // 2 5 0 0 1 0 1 + 0, // 0 00000000 + 0, // 1 00000000 + 1, // 2 00000001 + 2, // 3 00000010 + 0, // 4 00000000 + 4, // 5 00000100 + 3, // 6 00000011 + 8, // 7 00001000 + 0, // 8 00000000 + 0, // 9 00000000 + 5, // 10 00000101 + 16, 0, 32, 9, 6, 0, 64, 0, 128, 0, 10, 17, 256, 0, 0, 33, 0, 0, + 512,// 29 10000000 + 7 // 30 2 * 3 * 5 111 + }; public static int[] counts = new int[31]; @@ -29,12 +53,19 @@ public class Code03_TheNumberOfGoodSubsets { status[0] = (status[0] << 1) % mod; } for (int i = 2; i <= 30; i++) { - int cur = primes[i]; - if (cur != 0 && counts[i] != 0) { + // 2 几次 3 几次 4几次 5几次 30 几次 + int curPrimesStatus = primes[i]; + if (curPrimesStatus != 0 && counts[i] != 0) { + // curPrimesStatus K次 for (int from = 0; from < (1 << 10); from++) { - if ((from & cur) == 0) { - int to = from | cur; - status[to] = (int) (((long) status[to] + ((long) status[from] * counts[i])) % mod); + // from 11111111 + // 枚举所有的状态 from + // from & curPrimesStatus == 0 + if ((from & curPrimesStatus) == 0) { + // to + int to = from | curPrimesStatus; + status[to] = (int) (((long) status[to] + ((long) status[from] * counts[i])) % mod); +// // status[to] += status[from] * counts[i]; } } } diff --git a/算法周更班/class_2022_07_4_week/Code04_MatchsticksToSquare.java b/算法周更班/class_2022_07_4_week/Code04_MatchsticksToSquare.java deleted file mode 100644 index d57cb40..0000000 --- a/算法周更班/class_2022_07_4_week/Code04_MatchsticksToSquare.java +++ /dev/null @@ -1,40 +0,0 @@ -package class_2022_07_4_week; - -// 测试链接 : https://leetcode.cn/problems/matchsticks-to-square/ -public class Code04_MatchsticksToSquare { - - public static boolean makesquare(int[] matchsticks) { - int sum = 0; - for (int num : matchsticks) { - sum += num; - } - if ((sum & 3) != 0) { - return false; - } - int[] dp = new int[1 << matchsticks.length]; - return process(matchsticks, 0, 0, sum >> 2, 4, dp); - } - - public static boolean process(int[] arr, int status, int cur, int len, int edges, int[] dp) { - if (dp[status] != 0) { - return dp[status] == 1; - } - boolean ans = false; - if (edges == 0) { - ans = (status == (1 << arr.length) - 1) ? true : false; - } else { - for (int i = 0; i < arr.length && !ans; i++) { - if (((1 << i) & status) == 0 && cur + arr[i] <= len) { - if (cur + arr[i] == len) { - ans |= process(arr, status | (1 << i), 0, len, edges - 1, dp); - } else { - ans |= process(arr, status | (1 << i), cur + arr[i], len, edges, dp); - } - } - } - } - dp[status] = ans ? 1 : -1; - return ans; - } - -} diff --git a/算法课堂笔记/课堂内容汇总/每周有营养的大厂算法面试题(正在直播) b/算法课堂笔记/课堂内容汇总/每周有营养的大厂算法面试题(正在直播) index 7684717..a668863 100644 --- a/算法课堂笔记/课堂内容汇总/每周有营养的大厂算法面试题(正在直播) +++ b/算法课堂笔记/课堂内容汇总/每周有营养的大厂算法面试题(正在直播) @@ -1452,6 +1452,37 @@ Leetcode测试链接 : https://leetcode.cn/problems/rectangle-area-ii/ - +第033节 2022年7月第4周流行算法题目解析 + +一个数组如果满足 : +升降升降升降... 或者 降升降升...都是满足的 +给定一个数组， +1，看有几种方法能够剔除一个元素，达成上述的要求 +2，数组天然符合要求返回0 +3，剔除1个元素达成不了要求，返回-1， +比如： +给定[3, 4, 5, 3, 7]，返回3 +移除0元素，4 5 3 7 符合 +移除1元素，3 5 3 7 符合 +移除2元素，3 4 3 7 符合 +再比如：给定[1, 2, 3, 4] 返回-1 +因为达成不了要求 + +你将得到一个整数数组 matchsticks ，其中 matchsticks[i] 是第 i 个火柴棒的长度。 +你要用 所有的火柴棍 拼成一个正方形。 +你 不能折断 任何一根火柴棒，但你可以把它们连在一起，而且每根火柴棒必须 使用一次 。 +如果你能拼出正方形，则返回 true ，否则返回 false 。 +测试链接 : https://leetcode.cn/problems/matchsticks-to-square/ + +给你一个整数数组 nums 。如果 nums 的一个子集中， +所有元素的乘积可以表示为一个或多个 互不相同的质数 的乘积，那么我们称它为 好子集 。 +比方说，如果 nums = [1, 2, 3, 4] ： +[2, 3] ，[1, 2, 3] 和 [1, 3] 是 好 子集，乘积分别为 6 = 2*3 ，6 = 2*3 和 3 = 3 。 +[1, 4] 和 [4] 不是 好 子集，因为乘积分别为 4 = 2*2 和 4 = 2*2 。 +请你返回 nums 中不同的 好 子集的数目对 109 + 7 取余 的结果。 +nums 中的 子集 是通过删除 nums 中一些（可能一个都不删除，也可能全部都删除） +元素后剩余元素组成的数组。 +如果两个子集删除的下标不同，那么它们被视为不同的子集。 +测试链接 : https://leetcode.cn/problems/the-number-of-good-subsets/