Find number of occurrence of a string in given sentence

#include<stdio.h>     

void main()

{

  int i,j,t,count=0,flag;

  char st[100], s[100];

  printf("enter a sentence");

  gets(st);

  printf("\nenter the string whose occurrence we need to find");

  gets(s);

  for(i=0;st[i] != '\0';i++)

  {

            flag=0;

            for(j=0,t=i;s[j] != '\0'; j++,t++)

            {

                        if(st[t] != s[j])

                        {

                                    flag=1;

                                    break;

                        }

            }

            if(flag == 0)

                       count++;

   }

   printf("number of occurrences = %d", count);

}

(OR)

/*WITH OPTIMIZATION*/

#include<stdio.h>     

#include <string.h>

void main()

{

  int i,j,t,count=0,flag,len;

  char st[100], s[100];

  printf("enter a sentence");

  gets(st);

  printf("\nenter the string whose occurrence we need to find");

  gets(s);

  len=strlen(s);

  for(i=0;st[i+len-1] != '\0';i++)

  {

            flag=0;

            for(j=0,t=i;s[j] != '\0'; j++,t++)

            {

                        if(st[t] != s[j])

                        {

                                    flag=1;

                                    break;

                        }

            }

            if(flag == 0)

            {

                        count++;

                        i=i+len-1;

            }

   }

printf("number of occurrences = %d", count);

}

(OR)

/* USING STRTOK() FUNCTION*/
#include <string.h>

#include <stdio.h>

void main ()

 {

            char str[80] = "KLU is a great university. Iam a KLU student";

            char s[2] = " ";

             char *token;

             int count=0;

   

             token = strtok(str, s);

             while( token != NULL ) 

             {

                        if(strcmp(token,"KLU")== 0)

                                      count++; 

                        token = strtok(NULL, s);

            }

   

             printf("Number of occurrences=%d",count);

   

}