/*
* C Program To Count the Occurence of a Substring in String
 */
#include <stdio.h>
#include <string.h>

char str[100], sub[100];
int count = 0, count1 = 0;

void main()
{
    int i, j, l, l1, l2;
    printf("
           Enter a string : ");
           scanf("%[^
                ]s", str);
           l1 = strlen(str);
           printf("
                  Enter a substring : ");
                  scanf(" %[^
                       ]s", sub);
                  l2 = strlen(sub);
                  for (i = 0; i < l1;)
    {
        j = 0;
        count = 0;
        while ((str[i] == sub[j]))
                {
                    count++;
                    i++;
                    j++;
                }
            if (count == l2)
                {
                    count1++;
                    count = 0;
                }
            else
                i++;
        }
    printf("%s occurs %d times in %s", sub, count1, str);
}


Enter a string :
prrrogram c prrrogramming

Enter a substring :
rr
rr occurs 2 times in prrrogram c prrrogramming