```
class Solution {
public:
int coinChange(vector<int>& coins, int amount) {
vector<int> dp = vector<int>(amount + 1, amount + 1);
dp[0] = 0;
for (int i = 1; i <= amount; ++i) {
for (int j = 0; j < coins.size(); ++j) {
if (coins[j] <= i) dp[i] = std::min(dp[i], dp[i - coins[j]] + 1);
}
}
return dp[amount] == amount + 1 ? -1 : dp[amount];
}
};
```