编译出现异常，查不出有关问题

编译出现错误，查不出问题啊
小弟写了个小程序，就是查不出哪出错了，各位师傅帮帮忙啊，谢谢哈

用指针方式，将函数stract(s, t)将t指向的字符串复制到s指向的字符串的尾部。
#include <stdio.h>
#include <conio.h>
#include <stdlib.h>

int strlen(char *s);
void strcat(char *s, char *t);
void strcpy(char *s, char *t);

int main()
{
  int i, j;
  i = j =0;
  char *words = "hello, world";
  char *plus = ", I am comming.";
  i = strlen( words );
  j = strlen( plus );
  printf("i = %d\nj = %d\n\n", i, j);
  strcat(words, plus);
  i = strlen( words );
  printf("i = %d\n", i);
   
  getch();
  return 0;
} 

int strlen(char *s)
{
  char *p = s;
  while ( *p != '\0' )
  p++;
  return p - s;
}

void strcpy(char *s, char *t)
{
  while(*(s++) = *(t++))
  ;
}

void strcat(char *s, char *t)
{
  while(*s)
  ++s;
  strcpy(s, t);

}

[解决办法]

C/C++ code

#include <stdio.h>#include <conio.h>#include <stdlib.h>int strlen(char *s);void strcat(char *s, char *t);void strcpy(char *s, char *t);int main(){    int i, j;    //i = j =0;    char words[100] = "hello, world";  //用char * 初始化words为"hello, world"，不能通过words来修改"hello, world"    char *plus = ", I am comming.";    i = strlen( words );    j = strlen( plus );    printf("i = %d\nj = %d\n\n", i, j);    strcat(words, plus);    i = strlen( words );    printf("i = %d\n", i);    printf("%s\n", words);    //getchar();    return 0;}  int strlen(char *s){    char *p = s;    while ( *p != '\0' )        p++;    return p - s;}void strcpy(char s[100], char *t){    int i = strlen(s);    while(s[i++] = *(t++))        ;}void strcat(char s[], char *t){    //int i = 0;    //while(s[i++])        //++s;    strcpy(s, t);}
[解决办法]
char words[54] = "hello, world";、
改成这样，数组太小啦，words后面还要放", I am comming.",长度不够
[解决办法]
C/C++ code
int strlen(char *s);void strcat(char *s, char *t);void strcpy(char *s, char *t);int main(){    int i, j;    i = j =0;    char words[50] = "hello, world";    char *plus = ", I am comming.";    i = strlen( words );    j = strlen( plus );    printf("i = %d\nj = %d\n\n", i, j);    strcat(words, plus);    i = strlen( words );    printf("i = %d\n", i);    printf("%s",words);//    getch();    return 0;}  int strlen(char *s){    char *p = s;    while ( *p != '\0' )        p++;    return p - s;}void strcpy(char *s, char *t){    while(*(s++) = *(t++))    ;}void strcat(char *s, char *t){    while(*s)        ++s;    strcpy(s, t);}