#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int find (char string[],char sub[]); //returns array position of first time substring is found
int findFrom(char string[],char sub[],int n);  //returns array position of first time substring is found STARTING FROM n index position of main string.

int main()
{char string[200], sub[200], ch;
int i, index = -5;

printf("Enter the main string \n");
gets(string);

printf("Enter the substring: ");
gets(sub);


index = find(string, sub);

if (index < 0)
    printf("Substring not found");

else
    printf("Substring first found in %d position of the string",index+1);
    return 0;



}


int find (char string[],char sub[])
{int i, j = 0, k;
char ch;

for (i = 0; string[i]!= 0; i++)
{
    if (string[i] == sub[j])
    { k = i;
        while(sub[j]!=0)
        {
            if (string[k++] != sub[j++])
                break;
        }

        if (sub[j] == 0)
        {
            return i;       //a confirmed match has been found.
        }
        else
        {
            j = 0;
        }

    }

}


    return -1;


}

int findFrom(char string[],char sub[],int n)
{
int i, j = 0, k;
char ch;

for (i = n; string[i]!= 0; i++)
{
    if (string[i] == sub[j])
    { k = i;
        while(sub[j]!=0)
        {
            if (string[k++] != sub[j++])
                break;
        }

        if (sub[j] == 0)
        {
            return i;       //a confirmed match has been found.
        }
        else
        {
            j = 0;
        }

    }

}


    return -1;


}








//
Second code


#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int findFrom(char string[],char sub[]);  //returns array position of first time substring is found STARTING FROM n index position of main string.

int main()
{char string[200], sub[200], ch;
int i, index = -5, n = 0;

printf("Enter the main string \n");
gets(string);

printf("Enter the substring: ");
gets(sub);

for (i = 0; string[i]!= 0; i++)
{
    index = findFrom(string + n,sub);

    if (index > 0)
    {
        printf("%d ",index+n);
        i = index;
        n = index + n;
    }

    index = -1;
}


if (n == 0)
    printf("String not found.");




}




int findFrom(char string[],char sub[])
{
int i, j = 0, k;
char ch;

for (i = 0; string[i]!= 0; i++)
{
    if (string[i] == sub[j])
    { k = i;
        while(sub[j]!=0)
        {
            if (string[k++] != sub[j++])
                break;
        }

        if (sub[j] == 0)
        {
            return i;       //a confirmed match has been found.
        }
        else
        {
            j = 0;
        }

    }

}


    return -1;


}