func coinChange(coins []int, amount int) int {
if amount == 0 {
return 0
}
dp := make([]int, amount+1)
for i := 0; i <= amount; i++ {
dp[i] = amount+1
}
sort.Ints(coins)
n := len(coins)
dp[0]=0
for i := 1; i <= amount; i++ {
for j := 0; j < n; j++ {
if i < coins[j] {
break
}
dp[i] = min(dp[i], dp[i-coins[j]]+1)
}
}
if dp[amount] >amount {
return -1
}
return dp[amount]
}
func min(a,b int)int {
if a<b {
return a
}
return b
}