poj 2366 Sacrament of the sum

#include<cstdio>#include<cstring>#include<algorithm>#define maxn 50005using namespace std;int a[maxn],b[maxn];int n,m;bool check(int x){    int l=0,r=m-1;    while(l<r)    {        int mid=(l+r)>>1;        if(b[mid]>=x)r=mid;        else l=mid+1;    }    if(x==b[l])return 1;    return 0;}int main(){    while(scanf("%d",&n)!=EOF)    {        for(int i=0; i<n; i++) scanf("%d",&a[i]);        scanf("%d",&m);        for(int i=0; i<m; i++)        { scanf("%d",&b[i]); b[i]=10000-b[i];        }        sort(b,b+m);        bool flag=0;        for(int i=0;i<n;i++)        { if(check(a[i]))     {flag=1;break;}        }        if(flag)puts("YES");        else puts("NO");    }    return 0;}