Leetcode 322. Coin Change

322. Coin Change

没有AC,思路就是DP

322. Coin Change

You are given coins of different denominations and a total amount of money amount. Write a function to compute the fewest number of coins that you need to make up that amount. If that amount of money cannot be made up by any combination
of the coins, return 

-1

.

Example 1:

coins = 

[1, 2, 5]

, amount = 

11

return 

3

 (11 = 5 + 5 + 1)

Example 2:

coins = 

[2]

, amount = 

3

return 

-1

.

Note:

思路是DP, 然而注意一点如果在一位数字上仍是Integer.MAX_VALUE, 则不对这个数字位数进行任何操作

public class Solution {
public int coinChange(int[] coins, int amount) {
int[] dp = new int[amount + 1];
// int max = 0X
for(int i = 1; i <= amount; i++){
dp[i] = Integer.MAX_VALUE;
}

dp[0] = 0;
for(int i = 0; i <= amount; i++){
for(int j = 0; j < coins.length; j++){
if (dp[i] != Integer.MAX_VALUE && i + coins[j] <= amount)
dp[i + coins[j]] = Math.min(dp[i + coins[j]],dp[i] + 1);
}
}
return dp[amount] == Integer.MAX_VALUE? -1:dp[amount];
}
}