【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[10005];
int mon[105];
float fs[105];

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 = 0;
        for (i=1; i<=m; ++i) {
            scanf("%d %f", &mon[i], &fs[i]);
            fs[i] = 1 - fs[i];
            v += mon[i];
        }
        ff = 1 - ff;
        memset(dp, 0, sizeof(dp));
        dp[0] = 1;
        for (i=1; 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("
");
            */
        }
        for (i=v; i>0; --i)
            if (dp[i] >= ff)
                break;
        printf("%d
", i);
    }

    return 0;
}