hdu 1239 Calling Extraterrestrial Intelligence Again

#include<iostream>#include<cstring>#include<math.h>int num[100100];void init()//0 表示素数， 1表示不是素数 {int i,j;memset(num,0,sizeof(num));for(i=2;i<=sqrt(100000);i++){for(j=i*2;j<=100000;j=j+i){if(num[j]==0)num[j]=1;}}}int main(){init();int m,a,b;int i,j;while(scanf("%d%d%d",&m,&a,&b)!=EOF){if(m==0&&a==0&&b==0)break;int s=0;int pos1,pos2;for(i=2;i<=m;i++){if(num[i]==0){for(j=i;j<=m;j++){if(num[j]==0){if( (1.0*a)/(1.0*b)<=(1.0*i)/(1.0*j) &&i*j<=m){if(i*j>s){s=i*j;pos1=i;pos2=j;}}}}}}printf("%d %d\n",pos1,pos2);}return 0;}