hdu I NEED A OFFER!

 1 #include"iostream"
 2 #include"stdio.h"
 3 #include"algorithm"
 4 #include"string.h"
 5 #include"cmath"
 6 #include"queue"
 7 #define mx 10005
 8 using namespace std;
 9 int price[mx];
10 double chance[mx];
11 double dp[mx];
12 int main()
13 {
14     int n,m,i,j,k;
15     while(cin>>n>>m,n||m)
16     {
17         for(i=1;i<=m;i++)
18         {
19             cin>>price[i]>>chance[i];
20             chance[i]=1-chance[i];
21         }
22         for(i=0;i<=n;i++) dp[i]=1;
23         for(i=1;i<=m;i++)
24         {
25             for(j=n;j>=price[i];j--)
26             {
27                 if(dp[j]>dp[j-price[i]]*chance[i])dp[j]=dp[j-price[i]]*chance[i];
28             }
29         }
30         printf("%.1lf%%\n",(1-dp[n])*100);
31     }
32     return 0;
33 }