Sub String Given Main String Position

/* Write a C program that uses functions to perform the following operations:

   To insert a sub-string in to given main string from a given position. */

#include <stdio.h>

#include <conio.h>

#include <string.h>

void main()

{

char a[10];

char b[10];

char c[10];

int p=0,r=0,i=0;

int t=0;

int x,g,s,n,o;

clrscr();

puts("Enter First String:");

gets(a);

puts("Enter Second String:");

gets(b);

printf("Enter the position where the item has to be inserted: ");

scanf("%d",&p);

r = strlen(a);

n = strlen(b);

i=0;

// Copying the input string into another array

while(i <= r)

{

 c[i]=a[i];

 i++;

}

s = n+r;

o = p+n;

// Adding the sub-string

for(i=p;i<s;i++)

{

 x = c[i];

 if(t<n)

 {

  a[i] = b[t];

  t=t+1;

 }

 a[o]=x;

 o=o+1;

}

printf("%s", a);

getch();

}