// 1140. Stone Game II #include "leetcode.h" /* * alice and bob continue their games with piles of stones. there are a 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. * alice and bob take turns, with alice starting first. initiall, 'M = 1'. on * each player's turn, that player can take all the stones on the 'X' remaining * piles, where '1 <= X <= 2M'. then, we set 'M = max(M, X)'. the game continues * until all the stones have been take. assuming alice and bob play optimally, * return maximum stones alice can get. */ class Solution { public: int stoneGameII(vector &piles) { int n = piles.size(); vvd(int) dp(n + 1, vector(n + 1, 0)); vector sum(n + 1, 0); for (int i = n - 1; i >= 0; i--) sum[i] = sum[i + 1] + piles[i]; for (int i = 0; i <= n; i++) dp[i][n] = sum[i]; for (int i = n - 1; i >= 0; i--) for (int j = n - 1; j >= 1; j--) for (int k = 1; k <= 2 * j && i + j <= n; j++) dp[i][j] = max(dp[i][j], sum[i] - dp[i + k][max(j, k)]); return dp[0][1]; } }; int main() { Solution obj; vector p1 = {2, 7, 9, 4, 4}; vector p2 = {1, 2, 3, 4, 5, 100}; printf("%d\n", obj.stoneGameII(p1)); // expect: 10 printf("%d\n", obj.stoneGameII(p2)); // expect: 104 }