Assign true to the variable has_dups if the string s1 has any duplicate character (that is if any character appears more than once) and false otherwise.

#include <iostream>

using namespace std;

int main()

{

   string s;

   cin>>s;    //reading string

   int i,j;

   bool has_dups=false;

   int n= s.length();

   for(i=0;i<n;i++)  //to check for duplicate characters

   {

       for(j=0;j<n;j++)

       {

           if(j!=i && s[i]==s[j])  //to check if it is matched with itself

           {

               has_dups=true;  //if true no need to check others

               break;

           }

       }

   }

   cout<<has_dups;

   return 0;

}

OUTPUT :

California

1

Explanation:

Above program finds if a character repeat itself in the string entered by user.