这里不知道则么推导看一看:链接: 点击
class Solution {
public int coinChange(int[] coins, int amount) {
int n = coins.length;
int[][] dp = new int[n+1][amount+1];
int INF = 0x3f3f3f3f;//注意这题,找的是最小值,如果用-1表示会被更新进去导致错误
for(int i = 1; i <= amount; i++) dp[0][i] = INF;
for(int i = 1; i <= n; i++)
for(int j = 0; j <= amount; j++){
dp[i][j] = dp[i-1][j];
if(j >= coins[i-1])
dp[i][j] = Math.min(dp[i-1][j], dp[i][j-coins[i-1]]+1);//找的是最小值
}
return dp[n][amount] >= INF ? -1 : dp[n][amount];
}
}
这里不知道怎么优化可以看看:链接: 点击
int n = coins.length;
int[] dp = new int[amount+1];
int INF = 0x3f3f3f3f;//注意这题,找的是最小值,如果用-1表示会被更新进去导致错误
for(int i = 1; i <= amount; i++) dp[i] = INF;
for(int i = 1; i <= n; i++)
for(int j = 0; j <= amount; j++){
if(j >= coins[i-1])
dp[j] = Math.min(dp[j], dp[j-coins[i-1]]+1);//找的是最小值
}
return dp[amount] >= INF ? -1 : dp[amount];