C++ 二分查找的实现

#include <iostream>
#include <string>
using namespace std;
int main()
{
  int i,j,n,m;
  cin>>n;
  string *s1=new string [n];
  for(i=0;i<n;i++)
  {
    cin>>s1[i];
  }
  cin>>m;
  string *s2=new string [m];
  for(j=0;j<m;j++)
  {
    cin>>s2[j];
  }
  int s,t,flag,left,right;
  for(t=0;t<m;t++)
  {
    flag=0;
left=0,right=n;
    while(left<right)
    {
      for(s=(int)(left+right)/2;s<right;s++)
      {
        if((s2[t].compare(s1[s])==0)||(s2[t].compare(s1[0])==0))
        {
          flag=1;