【HDOJ】2955 Robberies

01背包。将最大金额作为容量v。概率做乘法。

 #include <stdio.h>
 #include <string.h>

 #define mymax(a, b) (a>b) ? a:b

 float dp[];
 int mon[];
 float fs[];

 int main() {
     int case_n;
     float ff, f;
     int m, v;
     int i, j;

     scanf("%d", &case_n);

     while (case_n--) {
         scanf("%f %d", &ff, &m);
         v = ;
         for (i=; i<=m; ++i) {
             scanf("%d %f", &mon[i], &fs[i]);
             fs[i] =  - fs[i];
             v += mon[i];
         }
         ff =  - ff;
         memset(dp, , sizeof(dp));
         dp[] = ;
         for (i=; i<=m; ++i) {
             for (j=v; j>=mon[i]; --j) {
                 dp[j] = mymax(dp[j], dp[j-mon[i]]*fs[i]);
             }
             /*
             for (j=0; j<=v; ++j) {
                 printf("%f ", dp[j]);
             }
             printf("\n");
             */
         }
         for (i=v; i>; --i)
             if (dp[i] >= ff)
                 break;
         printf("%d\n", i);
     }

     return ;
 }