题意：中文题
思路：求至少的话，就求都没有的情况，01背包
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int MAXN = 10005;
int a[MAXN];
int ai,n,m;
double f[MAXN],b[MAXN];
int main(){
while (scanf("%d%d",&n,&m) != EOF && n+m){
for (int i = 0; i < m; i++)
scanf("%d%lf",&a[i],&b[i]);
for (int i = 0; i <= n; i++)
f[i] = 1.0;
for (int i = 0; i < m; i++)
for (int j = n; j >= a[i]; j--)
f[j] = min(f[j],f[j-a[i]]*(1-b[i]));
printf("%.1lf%%\n",(1-f[n])*100);
}
return 0;
}