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package class46;
// 本题测试链接 : https://leetcode.com/problems/remove-boxes/
public class Code02_RemoveBoxes {
// arr[L...R]消除而且前面跟着K个arr[L]这个数
// 返回:所有东西都消掉,最大得分
public static int func1(int[] arr, int L, int R, int K) {
if (L > R) {
return 0;
}
int ans = func1(arr, L + 1, R, 0) + (K + 1) * (K + 1);
// 前面的K个X和arr[L]数合在一起了现在有K+1个arr[L]位置的数
for (int i = L + 1; i <= R; i++) {
if (arr[i] == arr[L]) {
ans = Math.max(ans, func1(arr, L + 1, i - 1, 0) + func1(arr, i, R, K + 1));
}
}
return ans;
}
public static int removeBoxes1(int[] boxes) {
int N = boxes.length;
int[][][] dp = new int[N][N][N];
int ans = process1(boxes, 0, N - 1, 0, dp);
return ans;
}
public static int process1(int[] boxes, int L, int R, int K, int[][][] dp) {
if (L > R) {
return 0;
}
if (dp[L][R][K] > 0) {
return dp[L][R][K];
}
int ans = process1(boxes, L + 1, R, 0, dp) + (K + 1) * (K + 1);
for (int i = L + 1; i <= R; i++) {
if (boxes[i] == boxes[L]) {
ans = Math.max(ans, process1(boxes, L + 1, i - 1, 0, dp) + process1(boxes, i, R, K + 1, dp));
}
}
dp[L][R][K] = ans;
return ans;
}
public static int removeBoxes2(int[] boxes) {
int N = boxes.length;
int[][][] dp = new int[N][N][N];
int ans = process2(boxes, 0, N - 1, 0, dp);
return ans;
}
public static int process2(int[] boxes, int L, int R, int K, int[][][] dp) {
if (L > R) {
return 0;
}
if (dp[L][R][K] > 0) {
return dp[L][R][K];
}
// 找到开头,
// 1,1,1,1,1,5
// 3 4 5 6 7 8
// !
int last = L;
while (last + 1 <= R && boxes[last + 1] == boxes[L]) {
last++;
}
// K个1 (K + last - L) last
int pre = K + last - L;
int ans = (pre + 1) * (pre + 1) + process2(boxes, last + 1, R, 0, dp);
for (int i = last + 2; i <= R; i++) {
if (boxes[i] == boxes[L] && boxes[i - 1] != boxes[L]) {
ans = Math.max(ans, process2(boxes, last + 1, i - 1, 0, dp) + process2(boxes, i, R, pre + 1, dp));
}
}
dp[L][R][K] = ans;
return ans;
}
}