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+// 877. Stone Game
+#include "leetcode.h"
+
+/*
+ * alice and bob play a game with piles of stones. there are an even number of
+ * piles arranged in a row, and each pile has a positive integer number of
+ * stones 'piles[i]'. the objective of the game is to end with the most stones.
+ * the total number of stones across all piles isodd, so there are no ties.
+ * alice and bob take turns, with alice starting first. each turn a player takes
+ * the entire pile of stones either from the beginning or from the end of the
+ * row. this continues until there are no more piles left, at which point the
+ * person with the most stones wins. assuming alice and bob play optimally,
+ * return 'true' if alice wins the game, or 'false' if bob wins.
+ */
+
+bool stoneGame(int *piles, int piles_size) {
+ int **dp = (int **)malloc(sizeof(int *) * piles_size);
+ int **sum = (int **)malloc(sizeof(int *) * piles_size);
+ for (int i = 0; i < piles_size; i++) {
+ dp[i] = (int *)malloc(sizeof(int) * piles_size);
+ sum[i] = (int *)malloc(sizeof(int) * piles_size);
+ for (int j = 0; j < piles_size; j++)
+ if (i == j) {
+ dp[i][j] = piles[i];
+ sum[i][j] = piles[i];
+ }
+ }
+ for (int l = 2; l <= piles_size; ++l)
+ for (int i = 0; i <= piles_size; ++i) {
+ int j = i + l - 1;
+ sum[i][j] = sum[i][j - 1] + piles[j];
+ dp[i][j] = sum[i][j] - fmin(dp[i][j - 1], dp[i + 1][j]);
+ }
+ bool ans = (dp[0][piles_size - 1] * 2 > sum[0][piles_size - 1]);
+ for (int i = 0; i < piles_size; i++)
+ free(dp[i]), free(sum[i]);
+ free(dp), free(sum);
+ return ans;
+}
+
+int main() {
+ int p1[] = {5, 3, 4, 5}, p2[] = {3, 7, 2, 3};
+ printf("%d\n", stoneGame(p1, ARRAY_SIZE(p1))); // expect: 1
+ printf("%d\n", stoneGame(p2, ARRAY_SIZE(p2))); // expect: 1
+}