c++ code not running

Question

//reverse a STRING
#include<iostream>
#include<cstring>
void reverse(char *a);
using namespace std;
int main()
{
char a[100]="keshav";

reverse(a);

}
void reverse(char *a)
{char temp;
int c=strlen(a),i;
for(i=0;i<c/2;i++)
{
temp=a[i];
a[i]=a[c-i];
a[c-i]=temp;

}

cout<<a<<endl;
}
it is not showing the output
please help!

Answer 1

Change it to:

for (i = 0; i < c/2; i++) {
temp = a[i];
a[i] = a[c-i-1];
a[c-i-1] = temp;
}

Strlen() returns the number of characters in the array, but the position of the characters in the array is strlen()-1 since array indices begin at 0. You have to substract 1 or else the last character in the array (the null terminator) is shifted to the beginning of the array and you end up with an empty string.