C Programming: Check whether a given substring is present in the given string

C String: Exercise-14 with Solution

Write a C program to check whether a given substring is present in the given string.

Sample Solution:

C Code:

#include <stdio.h>
void main()
{
	char str[80],search[20];	
	int c1=0,c2=0,i,j,flg;
	
       printf("\n\nCheck whether a given  substring is present in the given string :\n");
       printf("-------------------------------------------------------------------\n");	
	

        printf("Input the string : ");
        fgets(str, sizeof str, stdin);

	printf("Input the substring to be search : ");
	fgets(search, sizeof search, stdin);

	while (str[c1]!='\0')
		c1++;
                c1--;

	while (search[c2]!='\0')
		c2++;
                c2--;


	for(i=0;i<=c1-c2;i++)
	{ 
		for(j=i;j<i+c2;j++)
		{
			flg=1;
			if (str[j]!=search[j-i])
			{
				flg=0;
			   break;
			}
		}
		if (flg==1)
			break;
	}
	if (flg==1)
		printf("The substring exists in the string.\n\n");
	else
		printf("The substring is not exists in the string. \n\n");
}

Sample Output:

Check whether a given  substring is present in the given string :                                              
-------------------------------------------------------------------                                           
Input the string : This is a test string.                                                                     
Input the substring to be search : search                                                                     
The substring is not exists in the string.

Flowchart :

C Programming Code Editor:

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