C Program to Count the Occurrence of a Substring in String

This is a C Program to count the occurrence of a substring in string.

Problem Description

This program takes a string and a substring as input and counts the occurrence of a substring in string.

Problem Solution

1. Take a string and a substring as input.
2. Firstly check for the substring in the string.
3. If it is present then count the number of times it is present.

Program/Source Code

Here is source code of the C Program to count occurrence of a substring in string. The C program is successfully compiled and run on a Linux system. The program output is also shown below.

```
/* 
```

 * C Program To Count the Occurrence 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("\nEnter a string : ");
```
```
    scanf("%[^\n]s", str);
```
```
 
```
```
    l1 = strlen(str);
```
```
 
```
```
    printf("\nEnter a substring : ");
```
```
    scanf(" %[^\n]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);

```
}
```

Program Explanation

1. Take a string and a substring as input and store it in the array str and sub respectively.
2. Find the length of both the strings using strlen function.
3. Using for loop find whether the substring is present or not. If it is present then count the number of times it is present using the variable count.
4. Print the variable count as output.

Subscribe Now: C Programs Newsletter | Important Subjects Newsletters

Runtime Test Cases

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

Sanfoundry Global Education & Learning Series – 1000 C Programs.

Here’s the list of Best Books in C Programming, Data-Structures and Algorithms

Participate in C Programming Certification Contest of the Month Now!

If you wish to look at other example programs on Strings, go to C Programming Examples on Strings. If you wish to look at programming examples on all topics, go to C Programming Examples.

« Prev - C Program to Round Floor of Integer to Next Lower Power of 2

» Next - C Program to Find Sum of Numbers in Command Line Arguments Recursively

Next Steps: