[HIHO1353]满减优惠(状压,枚举)
题目链接:http://hihocoder.com/problemset/problem/1353
状压枚举
1 #include <bits/stdc++.h> 2 using namespace std; 3 4 const int maxn = 110; 5 int n, x, s; 6 int a[maxn]; 7 8 int main() { 9 // freopen("in", "r", stdin); 10 while(~scanf("%d%d",&n,&x)) { 11 s = 0; 12 for(int i = 1; i <= n; i++) { 13 scanf("%d", &a[i]); 14 s += a[i]; 15 } 16 int ret = 0x7f7f7f7f; 17 if(s < x) puts("-1"); 18 else { 19 int nn = 1 << n; 20 for(int i = 0; i < nn; i++) { 21 int t = 0; 22 for(int j = 0; j < n; j++) { 23 if((1 << j) & i) t += a[j+1]; 24 } 25 if(t >= x) ret = min(ret, t); 26 } 27 printf("%d\n", ret); 28 } 29 } 30 return 0; 31 }