modify code

pull/6/head
左程云 5 years ago
parent 10f70fbe68
commit 8f8a26a40a

@ -3,6 +3,52 @@ package class20;
// 测试链接https://leetcode.com/problems/longest-palindromic-subsequence/
public class Code01_PalindromeSubsequence {
public static int lpsl1(String s) {
if (s == null || s.length() == 0) {
return 0;
}
char[] str = s.toCharArray();
return f(str, 0, str.length - 1);
}
// str[L..R]最长回文子序列长度返回
public static int f(char[] str, int L, int R) {
if (L == R) {
return 1;
}
if (L == R - 1) {
return str[L] == str[R] ? 2 : 1;
}
int p1 = f(str, L + 1, R - 1);
int p2 = f(str, L, R - 1);
int p3 = f(str, L + 1, R);
int p4 = str[L] != str[R] ? 0 : (2 + f(str, L + 1, R - 1));
return Math.max(Math.max(p1, p2), Math.max(p3, p4));
}
public static int lpsl2(String s) {
if (s == null || s.length() == 0) {
return 0;
}
char[] str = s.toCharArray();
int N = str.length;
int[][] dp = new int[N][N];
dp[N - 1][N - 1] = 1;
for (int i = 0; i < N - 1; i++) {
dp[i][i] = 1;
dp[i][i + 1] = str[i] == str[i + 1] ? 2 : 1;
}
for (int L = N - 3; L >= 0; L--) {
for (int R = L + 2; R < N; R++) {
dp[L][R] = Math.max(dp[L][R - 1], dp[L + 1][R]);
if (str[L] == str[R]) {
dp[L][R] = Math.max(dp[L][R], 2 + dp[L + 1][R - 1]);
}
}
}
return dp[0][N - 1];
}
public static int longestPalindromeSubseq1(String s) {
if (s == null || s.length() == 0) {
return 0;

@ -2,6 +2,60 @@ package class20;
public class Code02_HorseJump {
// 当前来到的位置是x,y
// 还剩下rest步需要跳
// 跳完rest步正好跳到ab的方法数是多少
// 10 * 9
public static int jump(int a, int b, int k) {
return process(0, 0, k, a, b);
}
public static int process(int x, int y, int rest, int a, int b) {
if (x < 0 || x > 9 || y < 0 || y > 8) {
return 0;
}
if (rest == 0) {
return (x == a && y == b) ? 1 : 0;
}
int ways = process(x + 2, y + 1, rest - 1, a, b);
ways += process(x + 1, y + 2, rest - 1, a, b);
ways += process(x - 1, y + 2, rest - 1, a, b);
ways += process(x - 2, y + 1, rest - 1, a, b);
ways += process(x - 2, y - 1, rest - 1, a, b);
ways += process(x - 1, y - 2, rest - 1, a, b);
ways += process(x + 1, y - 2, rest - 1, a, b);
ways += process(x + 2, y - 1, rest - 1, a, b);
return ways;
}
public static int dp(int a, int b, int k) {
int[][][] dp = new int[10][9][k + 1];
dp[a][b][0] = 1;
for (int rest = 1; rest <= k; rest++) {
for (int x = 0; x < 10; x++) {
for (int y = 0; y < 9; y++) {
int ways = pick(dp, x + 2, y + 1, rest - 1);
ways += pick(dp, x + 1, y + 2, rest - 1);
ways += pick(dp, x - 1, y + 2, rest - 1);
ways += pick(dp, x - 2, y + 1, rest - 1);
ways += pick(dp, x - 2, y - 1, rest - 1);
ways += pick(dp, x - 1, y - 2, rest - 1);
ways += pick(dp, x + 1, y - 2, rest - 1);
ways += pick(dp, x + 2, y - 1, rest - 1);
dp[x][y][rest] = ways;
}
}
}
return dp[0][0][k];
}
public static int pick(int[][][] dp, int x, int y, int rest) {
if (x < 0 || x > 9 || y < 0 || y > 8) {
return 0;
}
return dp[x][y][rest];
}
public static int ways(int a, int b, int step) {
return f(0, 0, step, a, b);
}
@ -13,32 +67,22 @@ public class Code02_HorseJump {
if (step == 0) {
return (i == a && j == b) ? 1 : 0;
}
return f(i - 2, j + 1, step - 1, a, b)
+ f(i - 1, j + 2, step - 1, a, b)
+ f(i + 1, j + 2, step - 1, a, b)
+ f(i + 2, j + 1, step - 1, a, b)
+ f(i + 2, j - 1, step - 1, a, b)
+ f(i + 1, j - 2, step - 1, a, b)
+ f(i - 1, j - 2, step - 1, a, b)
+ f(i - 2, j - 1, step - 1, a, b);
return f(i - 2, j + 1, step - 1, a, b) + f(i - 1, j + 2, step - 1, a, b) + f(i + 1, j + 2, step - 1, a, b)
+ f(i + 2, j + 1, step - 1, a, b) + f(i + 2, j - 1, step - 1, a, b) + f(i + 1, j - 2, step - 1, a, b)
+ f(i - 1, j - 2, step - 1, a, b) + f(i - 2, j - 1, step - 1, a, b);
}
public static int waysdp(int a, int b, int s) {
int[][][] dp = new int[10][9][s+1];
int[][][] dp = new int[10][9][s + 1];
dp[a][b][0] = 1;
for(int step = 1 ; step <= s;step++ ) { // 按层来
for(int i = 0 ; i < 10;i++) {
for(int j = 0 ; j < 9; j++) {
dp[i][j][step] = getValue(dp,i - 2, j + 1, step - 1)
+ getValue(dp,i - 1, j + 2, step - 1)
+ getValue(dp,i + 1, j + 2, step - 1)
+ getValue(dp,i + 2, j + 1, step - 1)
+ getValue(dp,i + 2, j - 1, step - 1)
+ getValue(dp,i + 1, j - 2, step - 1)
+ getValue(dp,i - 1, j - 2, step - 1)
+ getValue(dp,i - 2, j - 1, step - 1);
for (int step = 1; step <= s; step++) { // 按层来
for (int i = 0; i < 10; i++) {
for (int j = 0; j < 9; j++) {
dp[i][j][step] = getValue(dp, i - 2, j + 1, step - 1) + getValue(dp, i - 1, j + 2, step - 1)
+ getValue(dp, i + 1, j + 2, step - 1) + getValue(dp, i + 2, j + 1, step - 1)
+ getValue(dp, i + 2, j - 1, step - 1) + getValue(dp, i + 1, j - 2, step - 1)
+ getValue(dp, i - 1, j - 2, step - 1) + getValue(dp, i - 2, j - 1, step - 1);
}
}
}
@ -58,6 +102,8 @@ public class Code02_HorseJump {
int y = 7;
int step = 10;
System.out.println(ways(x, y, step));
System.out.println(waysdp(x, y, step));
System.out.println(dp(x, y, step));
System.out.println(jump(x, y, step));
}
}

@ -14,14 +14,14 @@ import java.util.PriorityQueue;
// 假设时间点从0开始返回所有人喝完咖啡并洗完咖啡杯的全部过程结束后至少来到什么时间点。
public class Code03_Coffee {
// 方法一:暴力尝试方法
public static int minTime1(int[] arr, int n, int a, int b) {
// 验证的方法,彻底的暴力,不要脸的暴力
public static int right(int[] arr, int n, int a, int b) {
int[] times = new int[arr.length];
int[] drink = new int[n];
return forceMake(arr, times, 0, drink, n, a, b);
}
// 方法一,每个人暴力尝试用每一个咖啡机给自己做咖啡
// 每个人暴力尝试用每一个咖啡机给自己做咖啡
public static int forceMake(int[] arr, int[] times, int kth, int[] drink, int n, int a, int b) {
if (kth == n) {
int[] drinkSorted = Arrays.copyOf(drink, kth);
@ -41,7 +41,6 @@ public class Code03_Coffee {
return time;
}
// 方法一,暴力尝试洗咖啡杯的方式
public static int forceWash(int[] drinks, int a, int b, int index, int washLine, int time) {
if (index == drinks.length) {
return time;
@ -56,7 +55,7 @@ public class Code03_Coffee {
return Math.min(ans1, ans2);
}
// 方法二:稍微好一点的解法
// 以下为贪心+优良暴力
public static class Machine {
public int timePoint;
public int workTime;
@ -76,8 +75,8 @@ public class Code03_Coffee {
}
// 方法二,每个人暴力尝试用每一个咖啡机给自己做咖啡,优化成贪心
public static int minTime2(int[] arr, int n, int a, int b) {
// 优良一点的暴力尝试的方法
public static int minTime1(int[] arr, int n, int a, int b) {
PriorityQueue<Machine> heap = new PriorityQueue<Machine>(new MachineComparator());
for (int i = 0; i < arr.length; i++) {
heap.add(new Machine(0, arr[i]));
@ -89,66 +88,32 @@ public class Code03_Coffee {
drinks[i] = cur.timePoint;
heap.add(cur);
}
return process(drinks, a, b, 0, 0);
}
// 方法二,洗咖啡杯的方式和原来一样,只是这个暴力版本减少了一个可变参数
// process(drinks, 3, 10, 0,0)
// a 洗一杯的时间 固定变量
// b 自己挥发干净的时间 固定变量
// drinks 每一个员工喝完的时间 固定变量
// drinks[0..index-1]都已经干净了,不用你操心了
// drinks[index...]都想变干净这是我操心的washLine表示洗的机器何时可用
// drinks[index...]变干净,最少的时间点返回
public static int process(int[] drinks, int a, int b, int index, int washLine) {
if (index == drinks.length - 1) {
return Math.min(Math.max(washLine, drinks[index]) + a, drinks[index] + b);
}
// 剩不止一杯咖啡
// wash是我当前的咖啡杯洗完的时间
int wash = Math.max(washLine, drinks[index]) + a;// 洗index一杯结束的时间点
// index+1...变干净的最早时间
int next1 = process(drinks, a, b, index + 1, wash);
// index....
int p1 = Math.max(wash, next1);
int dry = drinks[index] + b; // 挥发index一杯结束的时间点
int next2 = process(drinks, a, b, index + 1, washLine);
int p2 = Math.max(dry, next2);
return Math.min(p1, p2);
return bestTime(drinks, a, b, 0, 0);
}
public static int dp(int[] drinks, int a, int b) {
if (a >= b) {
return drinks[drinks.length - 1] + b;
}
// a < b
int N = drinks.length;
int limit = 0; // 咖啡机什么时候可用
for (int i = 0; i < N; i++) {
limit = Math.max(limit, drinks[i]) + a;
}
int[][] dp = new int[N][limit + 1];
// N-1行所有的值
for (int washLine = 0; washLine <= limit; washLine++) {
dp[N - 1][washLine] = Math.min(Math.max(washLine, drinks[N - 1]) + a, drinks[N - 1] + b);
}
for (int index = N - 2; index >= 0; index--) {
for (int washLine = 0; washLine <= limit; washLine++) {
int p1 = Integer.MAX_VALUE;
int wash = Math.max(washLine, drinks[index]) + a;
if (wash <= limit) {
p1 = Math.max(wash, dp[index + 1][wash]);
}
int p2 = Math.max(drinks[index] + b, dp[index + 1][washLine]);
dp[index][washLine] = Math.min(p1, p2);
}
// drinks 所有杯子可以开始洗的时间
// wash 单杯洗干净的时间(串行)
// air 挥发干净的时间(并行)
// free 洗的机器什么时候可用
// drinks[index.....]都变干净,最早的结束时间(返回)
public static int bestTime(int[] drinks, int wash, int air, int index, int free) {
if (index == drinks.length) {
return 0;
}
return dp[0][0];
// index号杯子 决定洗
int selfClean1 = Math.max(drinks[index], free) + wash;
int restClean1 = bestTime(drinks, wash, air, index + 1, selfClean1);
int p1 = Math.max(selfClean1, restClean1);
// index号杯子 决定挥发
int selfClean2 = drinks[index] + air;
int restClean2 = bestTime(drinks, wash, air, index + 1, free);
int p2 = Math.max(selfClean2, restClean2);
return Math.min(p1, p2);
}
// 方法三:最终版本,把方法二洗咖啡杯的暴力尝试进一步优化成动态规划
public static int minTime3(int[] arr, int n, int a, int b) {
// 方法二,贪心+优良尝试改成动态规划
public static int minTime2(int[] arr, int n, int a, int b) {
PriorityQueue<Machine> heap = new PriorityQueue<Machine>(new MachineComparator());
for (int i = 0; i < arr.length; i++) {
heap.add(new Machine(0, arr[i]));
@ -160,18 +125,29 @@ public class Code03_Coffee {
drinks[i] = cur.timePoint;
heap.add(cur);
}
if (a >= b) {
return drinks[n - 1] + b;
return bestTimeDp(drinks, a, b);
}
int[][] dp = new int[n][drinks[n - 1] + n * a];
for (int i = 0; i < dp[0].length; i++) {
dp[n - 1][i] = Math.min(Math.max(i, drinks[n - 1]) + a, drinks[n - 1] + b);
}
for (int row = n - 2; row >= 0; row--) { // row 咖啡杯的编号
int washLine = drinks[row] + (row + 1) * a;
for (int col = 0; col < washLine; col++) {
int wash = Math.max(col, drinks[row]) + a;
dp[row][col] = Math.min(Math.max(wash, dp[row + 1][wash]), Math.max(drinks[row] + b, dp[row + 1][col]));
public static int bestTimeDp(int[] drinks, int wash, int air) {
int N = drinks.length;
int maxFree = 0;
for (int i = 0; i < drinks.length; i++) {
maxFree = Math.max(maxFree, drinks[i]) + wash;
}
int[][] dp = new int[N + 1][maxFree + 1];
for (int index = N - 1; index >= 0; index--) {
for (int free = 0; free <= maxFree; free++) {
int selfClean1 = Math.max(drinks[index], free) + wash;
if (selfClean1 > maxFree) {
break; // 因为free后面的也都不用填了
}
int restClean1 = dp[index + 1][selfClean1];
int p1 = Math.max(selfClean1, restClean1);
// index号杯子 决定挥发
int selfClean2 = drinks[index] + air;
int restClean2 = dp[index + 1][free];
int p2 = Math.max(selfClean2, restClean2);
dp[index][free] = Math.min(p1, p2);
}
}
return dp[0][0];
@ -196,12 +172,6 @@ public class Code03_Coffee {
}
public static void main(String[] args) {
int[] test = { 1, 1, 5, 5, 7, 10, 12, 12, 12, 12, 12, 12, 15 };
int a1 = 3;
int b1 = 10;
System.out.println(process(test, a1, b1, 0, 0));
System.out.println(dp(test, a1, b1));
int len = 5;
int max = 9;
int testTime = 50000;
@ -210,9 +180,9 @@ public class Code03_Coffee {
int n = (int) (Math.random() * 5) + 1;
int a = (int) (Math.random() * 5) + 1;
int b = (int) (Math.random() * 10) + 1;
int ans1 = minTime1(arr, n, a, b);
int ans2 = minTime2(arr, n, a, b);
int ans3 = minTime3(arr, n, a, b);
int ans1 = right(arr, n, a, b);
int ans2 = minTime1(arr, n, a, b);
int ans3 = minTime2(arr, n, a, b);
if (ans1 != ans2 || ans2 != ans3) {
printArray(arr);
System.out.println("n : " + n);

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