C++ program to check whether a string is palindrome or not

Here are C++ programs to check whether a string is palindrome or not using recursion,using functions, using pointers, without using inbuilt functions etc.

Method 1 : C++ program to check whether a string is palindrome or not

#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
int main()
{
    char a[10],rev[10],*ft,*lt;
    cout<<"Enter the string ";
    gets(a);
    strcpy(rev,a);
    strrev(rev);
    if(strcmp(a,rev)==0)
      cout<<"String is palindrome ";
    else
      cout<<"String is not palindrome";
    return 0;
}

Method 2 : C++ program to check whether a string is palindrome or not using pointers

#include<iostream>
#include<string.h>
#include<stdio.h>
using namespace std;
int main()
{
    char a[10],*ft,*lt,flag=1;
    int i,y;
    cout<<"Enter the string ";
    gets(a);
    i=strlen(a)-1;
    lt=&a[i];
    ft=&a[0];
    for(y=i;y>=i/2;y--,ft++,lt--)
      if(*lt!=*ft)
         flag=0;
    if(flag==1)
      cout<<"String is palindrome ";
    else
      cout<<"String is not palindrome ";
    return 0;
}

Method 3 : C++ program to check whether a string is palindrome or not using functions

#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
int compare(char a[10])
{
    char rev[10];
    strcpy(rev,a);
    strrev(rev);
    if(strcmp(a,rev)==0)
        return 1;
    else
      return 0;

}
int main()
{
    char a[10],*ft,*lt;
    cout<<"Enter the string ";
    gets(a);
    if(compare(a))
      cout<<"String is palindrome ";
    else
      cout<<"String is not palindrome ";
    return 0;
}

Method 4 : C++ program to check whether a string is palindrome or not using without using any in-built functions

#include<iostream>
#include<stdio.h>
#include<string.h>
using namespace std;
int main()
{
    char a[10],lt;
    cout<<"Enter the string ";
    gets(a);
    lt=strlen(a)-1;
    for(int i=0;i<=lt/2;i++)
        if(a[lt-i]!=a[i])
        {
            cout<<"String is not palindrome ";
            return 0;
        }
    cout<<"String is palindrome ";
    return 0;
}

Method 5 : C++ program to check whether a string is palindrome or not using recursion

#include<iostream>
#include<string.h>
using namespace std;
void cpalin(char *str,int i,int j)
{
    if(i>j)
    {
        cout<<"String is palindrome";
        return ;
    }
    else if(str[i]!=str[j])
    {
        cout<<"String is not palindrome";
        return ;
    }
    cpalin(str,i+1,j-1);
}
int main()
{
    char str[50];
    int lenght;
    cout<<"Enter string : ";
    cin>>str;
    cpalin(str,0,strlen(str)-1);
    return 0;
}