diff --git a/src/class44/DC3.java b/src/class44/DC3.java index acf1fa0..47e7601 100644 --- a/src/class44/DC3.java +++ b/src/class44/DC3.java @@ -8,6 +8,11 @@ public class DC3 { public int[] height; + // 构造方法的约定: + // 数组叫nums，如果你是字符串，请转成整型数组nums + // 数组中，最小值>=1 + // 如果不满足，处理成满足的，也不会影响使用 + // max, nums里面最大值是多少 public DC3(int[] nums, int max) { sa = sa(nums, max); rank = rank(); @@ -152,7 +157,7 @@ public class DC3 { // 为了测试 public static void main(String[] args) { - int len = 3000000; + int len = 100000; int maxValue = 100; long start = System.currentTimeMillis(); new DC3(randomArray(len, maxValue), maxValue); diff --git a/src/class44/Code02_InsertS2MakeMostAlphabeticalOrder.java b/src/class45/Code01_InsertS2MakeMostAlphabeticalOrder.java similarity index 98% rename from src/class44/Code02_InsertS2MakeMostAlphabeticalOrder.java rename to src/class45/Code01_InsertS2MakeMostAlphabeticalOrder.java index 2641ac5..adc697f 100644 --- a/src/class44/Code02_InsertS2MakeMostAlphabeticalOrder.java +++ b/src/class45/Code01_InsertS2MakeMostAlphabeticalOrder.java @@ -1,6 +1,6 @@ -package class44; +package class45; -public class Code02_InsertS2MakeMostAlphabeticalOrder { +public class Code01_InsertS2MakeMostAlphabeticalOrder { // 暴力方法 public static String right(String s1, String s2) { diff --git a/src/class44/Code03_CreateMaximumNumber.java b/src/class45/Code02_CreateMaximumNumber.java similarity index 99% rename from src/class44/Code03_CreateMaximumNumber.java rename to src/class45/Code02_CreateMaximumNumber.java index 10cddd9..72b2830 100644 --- a/src/class44/Code03_CreateMaximumNumber.java +++ b/src/class45/Code02_CreateMaximumNumber.java @@ -1,7 +1,7 @@ -package class44; +package class45; // 测试链接: https://leetcode.com/problems/create-maximum-number/ -public class Code03_CreateMaximumNumber { +public class Code02_CreateMaximumNumber { public static int[] maxNumber1(int[] nums1, int[] nums2, int k) { int len1 = nums1.length; diff --git a/src/class44/Code04_LongestCommonSubstringConquerByHeight.java b/src/class45/Code03_LongestCommonSubstringConquerByHeight.java similarity index 98% rename from src/class44/Code04_LongestCommonSubstringConquerByHeight.java rename to src/class45/Code03_LongestCommonSubstringConquerByHeight.java index b7b9a20..042af59 100644 --- a/src/class44/Code04_LongestCommonSubstringConquerByHeight.java +++ b/src/class45/Code03_LongestCommonSubstringConquerByHeight.java @@ -1,4 +1,4 @@ -package class44; +package class45; // 最长公共子串问题是面试常见题目之一 // 假设str1长度N，str2长度M @@ -9,7 +9,7 @@ package class44; // 进而用sa数组去生成height数组 // 而且在生成的时候，还有一个不回退的优化，都非常不容易理解 // 这就是后缀数组在面试算法中的地位 : 德高望重的噩梦 -public class Code04_LongestCommonSubstringConquerByHeight { +public class Code03_LongestCommonSubstringConquerByHeight { public static int lcs1(String s1, String s2) { if (s1 == null || s2 == null || s1.length() == 0 || s2.length() == 0) { diff --git a/src/class45/Code04_MaxSumLengthNoMore.java b/src/class45/Code04_MaxSumLengthNoMore.java new file mode 100644 index 0000000..f9d7c8c --- /dev/null +++ b/src/class45/Code04_MaxSumLengthNoMore.java @@ -0,0 +1,100 @@ +package class45; + +import java.util.LinkedList; + +// 给定一个数组arr，和一个正数M +// 返回在子数组长度不大于M的情况下，最大的子数组累加和 +public class Code04_MaxSumLengthNoMore { + + // O(N^2)的解法，暴力解，用作对数器 + public static int test(int[] arr, int M) { + if (arr == null || arr.length == 0 || M < 1) { + return 0; + } + int N = arr.length; + int max = Integer.MIN_VALUE; + for (int L = 0; L < N; L++) { + int sum = 0; + for (int R = L; R < N; R++) { + if (R - L + 1 > M) { + break; + } + sum += arr[R]; + max = Math.max(max, sum); + } + } + return max; + } + + // O(N)的解法，最优解 + public static int maxSum(int[] arr, int M) { + if (arr == null || arr.length == 0 || M < 1) { + return 0; + } + int N = arr.length; + int[] sum = new int[N]; + sum[0] = arr[0]; + for (int i = 1; i < N; i++) { + sum[i] = sum[i - 1] + arr[i]; + } + LinkedList qmax = new LinkedList<>(); + int i = 0; + int end = Math.min(N, M); + for (; i < end; i++) { + while (!qmax.isEmpty() && sum[qmax.peekLast()] <= sum[i]) { + qmax.pollLast(); + } + qmax.add(i); + } + int max = sum[qmax.peekFirst()]; + int L = 0; + for (; i < N; L++, i++) { + if (qmax.peekFirst() == L) { + qmax.pollFirst(); + } + while (!qmax.isEmpty() && sum[qmax.peekLast()] <= sum[i]) { + qmax.pollLast(); + } + qmax.add(i); + max = Math.max(max, sum[qmax.peekFirst()] - sum[L]); + } + for (; L < N - 1; L++) { + if (qmax.peekFirst() == L) { + qmax.pollFirst(); + } + max = Math.max(max, sum[qmax.peekFirst()] - sum[L]); + } + return max; + } + + // 用作测试 + public static int[] randomArray(int len, int max) { + int[] arr = new int[len]; + for (int i = 0; i < len; i++) { + arr[i] = (int) (Math.random() * max) - (int) (Math.random() * max); + } + return arr; + } + + // 用作测试 + public static void main(String[] args) { + int maxN = 50; + int maxValue = 100; + int testTime = 1000000; + System.out.println("测试开始"); + for (int i = 0; i < testTime; i++) { + int N = (int) (Math.random() * maxN); + int M = (int) (Math.random() * maxN); + int[] arr = randomArray(N, maxValue); + int ans1 = test(arr, M); + int ans2 = maxSum(arr, M); + if (ans1 != ans2) { + System.out.println(ans1); + System.out.println(ans2); + System.out.println("Oops!"); + } + } + System.out.println("测试结束"); + } + +} diff --git a/src/class45/Code01_BurstBalloons.java b/src/class46/Code01_BurstBalloons.java similarity index 99% rename from src/class45/Code01_BurstBalloons.java rename to src/class46/Code01_BurstBalloons.java index e58ec01..edacdda 100644 --- a/src/class45/Code01_BurstBalloons.java +++ b/src/class46/Code01_BurstBalloons.java @@ -1,4 +1,4 @@ -package class45; +package class46; public class Code01_BurstBalloons { diff --git a/src/class45/Code02_RemoveBoxes.java b/src/class46/Code02_RemoveBoxes.java similarity index 98% rename from src/class45/Code02_RemoveBoxes.java rename to src/class46/Code02_RemoveBoxes.java index 6a9f2f8..2c724e0 100644 --- a/src/class45/Code02_RemoveBoxes.java +++ b/src/class46/Code02_RemoveBoxes.java @@ -1,4 +1,4 @@ -package class45; +package class46; public class Code02_RemoveBoxes { diff --git a/src/class45/Code03_DeleteAdjacentSameCharacter.java b/src/class46/Code03_DeleteAdjacentSameCharacter.java similarity index 99% rename from src/class45/Code03_DeleteAdjacentSameCharacter.java rename to src/class46/Code03_DeleteAdjacentSameCharacter.java index 124e9d5..f0aa370 100644 --- a/src/class45/Code03_DeleteAdjacentSameCharacter.java +++ b/src/class46/Code03_DeleteAdjacentSameCharacter.java @@ -1,4 +1,4 @@ -package class45; +package class46; // 如果一个字符相邻的位置没有相同字符，那么这个位置的字符出现不能被消掉 // 比如:"ab"，其中a和b都不能被消掉 diff --git a/src/class46/Code01_StrangePrinter.java b/src/class47/Code01_StrangePrinter.java similarity index 97% rename from src/class46/Code01_StrangePrinter.java rename to src/class47/Code01_StrangePrinter.java index 679305b..9044ac7 100644 --- a/src/class46/Code01_StrangePrinter.java +++ b/src/class47/Code01_StrangePrinter.java @@ -1,4 +1,4 @@ -package class46; +package class47; public class Code01_StrangePrinter { diff --git a/src/class46/Code02_RestoreWays.java b/src/class47/Code02_RestoreWays.java similarity index 99% rename from src/class46/Code02_RestoreWays.java rename to src/class47/Code02_RestoreWays.java index dddfcb9..4bcf8d0 100644 --- a/src/class46/Code02_RestoreWays.java +++ b/src/class47/Code02_RestoreWays.java @@ -1,4 +1,4 @@ -package class46; +package class47; // 整型数组arr长度为n(3 <= n <= 10^4)，最初每个数字是<=200的正数且满足如下条件： // 1. 0位置的要求：arr[0]<=arr[1]