1048. Find Coins

不要使用遍历方式以此查找，会出现超时。

#include <cstdio>#include <vector>using namespace std;#define MAX 1020vector<int>face ;int main(void){int n , amount ;int i ;bool flag = false ;face.assign(MAX + 1, 0 );//freopen("input.txt" , "r" , stdin);scanf("%d %d" , &n , &amount);while(n--){int value ;scanf("%d" , &value);face[value]++ ;}for( i = 1 ; i <= amount/2 ; i++){face[i]-- ;face[amount - i] -- ;if( face[i]>= 0 && face[amount - i]>=0){flag  =true ;printf("%d %d\n" , i , amount - i);break ;}}if(!flag)printf("No Solution\n");return 0;}