CPP回文数判断

找到中点，向两侧延伸判断

#include<iostream>
#include<bits/stdc++.h>//strstr,strcpy,strlen求字符串数组，.length()用于string 
 
using namespace std;
int main()
{
	string s;//从0开始 
	cin>>s;
	int l=s.length();
	//cout<<l;
	int mid=l/2;
	int left,right;
	if(l%2==0)
	{
		left=mid-1;
		right=mid;
	}
	if(l%2==1){
		left=mid-1;
		right=mid+1;
//	cout<<left<<' '<<right<<endl; 
	}
	int flag=1;
	for(int i=1;i<=mid;i++)
	{
		if(s[left]!=s[right])
		{
			flag=0;
			break;
		}
		left--;
		right++;
	}
	if(flag==1)cout<<'Y'<<endl;
	if(flag==0) cout<<'N'<<endl;
	return 0;
}