贪心 Codeforces Round #109 (Div. 2) B. Combination

题目传送门

 /*
     贪心：按照能选的个数和点数降序排序，当条件不符合就break，水题啊！
 */
 #include <cstdio>
 #include <algorithm>
 #include <cstring>
 #include <cmath>
 using namespace std;

 const int MAXN = 1e3 + ;
 const int INF = 0x3f3f3f3f;
 struct Card
 {
     int a, b;
 }card[MAXN];

 bool cmp(Card x, Card y)
 {
     if (x.b == y.b)    return x.a > y.a;
     return x.b > y.b;
 }

 int main(void)        //Codeforces Round #109 (Div. 2) B. Combination
 {
 //    freopen ("B.in", "r", stdin);

     int n;
     while (scanf ("%d", &n) == )
     {
         for (int i=; i<=n; ++i)
         {
             scanf ("%d%d", &card[i].a, &card[i].b);
         }
         sort (card+, card++n, cmp);

         int ans = ;    int res = ;    int cnt = ;
         for (int i=; i<=n; ++i)
         {
             res += card[i].b - ;    ans += card[i].a;
             cnt = cnt -  + card[i].b;
             if (cnt <= )    break;
             if (res <= )    break;
         }

         printf ("%d\n", ans);
     }

     return ;
 }