Leetcode 322. 零钱兑换 动态规划

原题链接：Leetcode 322. 零钱兑换

class Solution {
public:
    int coinChange(vector<int>& coins, int amount) {
        if (amount == 0)
            return 0;
        int n = coins.size();
        //dp[i]表示凑成总金额i所需的最少的硬币个数
        int dp[amount + 1];
        dp[0] = 0;
        for (int i = 1; i <= amount; i++) {
            dp[i] = INT_MAX;
            for (auto x : coins) {
                if (i == x)
                    dp[i] = 1;
                else if (i - x > 0 && dp[i - x] != INT_MAX) {
                    dp[i] = min(dp[i], dp[i - x] + 1);
                }
            }
        }
        return dp[amount] == INT_MAX ? -1 : dp[amount];
    }
};