求一个字符串中最长的相同字符字串 不区分大小写

#include<iostream>#include<string>#include<cstdlib>using namespace std;string getLongest(string s){ int n = s.length(); if(n<=1)    return s;     int start = 0; int count = 1; int max = 1; char flag = tolower(s[0]); for(int i=1;i<n;i++) {    if(tolower(s[i])==flag)    {        ++count;         flag = tolower(s[i]);}else{if(max<count){max = count;start = i-max;}count = 1;flag = tolower(s[i]);}  }  // cout<<max<<endl; // cout<<count<<endl; // cout<<start<<endl;      if(max<count)  {       max = count;   start = n-max;  }    return s.substr(start,max); }   int main() {   string s;   cin>>s;   cout<<getLongest(s)<<endl;   return 0; }