杭电acm2111

贪心

#include <stdio.h>#include <algorithm>using namespace std;struct jewelry {int price;int volume;bool operator < (const jewelry &A) const {return price > A.price;}}buf[101];int main() {int v, n, i, ans, ids;while(~scanf("%d", &v) && v) {scanf("%d", &n);for(i=0; i<n; i++)scanf("%d%d", &buf[i].price, &buf[i].volume);sort(buf, buf+n);ids = 0;ans = 0;while(v>0 && ids<n) {if(v>=buf[ids].volume) {v -= buf[ids].volume;ans += buf[ids].price * buf[ids].volume;} else {ans += v * buf[ids].price;v = 0;}ids ++;}printf("%d\n", ans);}return 0;}