动态规划——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:

You may assume that you have an infinite number of each kind of coin.

d[i]表示 凑到i数值所用的最小硬币数
递推公式
d[i]=min(d[i],d[i-coins[j]]+1)

i时  等于 i-coins[j] +1的最小值，为了方便比较将所有的d[i] 初始化为最大值 0x7ffffffe 

public class Solution {
public int coinChange(int[] coins, int amount) {
int [] d=new int[amount+1];
d[0]=0;
final int INF = 0x7ffffffe;
for (int i = 1; i <= amount; i++) d[i] = INF;
for(int i=1;iamount?-1:d[amount];
}
}