新学者求注释一下程序越详细越好

#include  <conio.h>
#include  <stdio.h>
#include  <string.h>
#include <stdlib.h>
int fun(char *s, char *t)
{  int n;
   char *p, *r;
  n = 0;
while(*s){p = s;
 r = t;
while(*r)
if(*r == *p)
{
r++;  p++;
} else
break;
    if(r == '\0')n++;
s++;}
  return  n;
}main( )
{    char s[100], t[100];
   int m;
  system("cls");
  printf("\nPlease enter string S:" );
scanf("%s", s);
  printf("\nPlease enter substring t:");
scanf("%s", t);
m = fun(s, t);
printf("\nThe result is : m = %d\n", m);}

就是输入一个字符串，再输入一个子字符串，判断是否相等

#include  <conio.h>
#include  <stdio.h>
#include  <string.h>
#include <stdlib.h>
int fun(char *s, char *t)//寻找函数
{
    int n;
    char *p, *r;
    n = 0;
    while(*s)
    {
        p = s;
        r = t;
        while(*r)//如果不为空一直循环直到结束
            if(*r == *p)
            {
                r++;
                p++;
            }
            else//不相等退出
                break;
        if(r == '\0')
            n++;
        s++;
    }
    return  n;
}
main( )
{
    char s[100], t[100];
    int m;
    system("cls");
    printf("\nPlease enter string S:" );//输入母字符串
    scanf("%s", s);
    printf("\nPlease enter substring t:");//输入子字符串
    scanf("%s", t);
    m = fun(s, t);
    printf("\nThe result is : m = %d\n", m);
}