c++中 写一个两个字符串相连接的函数：char *strcat(char *s1,const char *s2) 其作用是将s2接到s1的末端

c++中 写一个两个字符串相连接的函数：char *strcat(char *s1,const char *s2) 其作用是将s2接到s1的末端

#include
char *strcat(char *s1, const char *s2)
{
char *p;
p = s1;
while(*p)
p++;
while(*p++ = *s2++);
return s1;
}
int main()
{
char s1[10] = "abc";
char s2[4] = "123";
char *p = strcat(s1, s2);
cout << p << endl;
return 0;
}

char *strcat(char *s1,const char *s2)
{
char *p1=s1,*p2=(char *)s2;
while (*p1) ++p1;
while (*p2) *p1++=*p2++;
*p1=0;
return s1;
}

#include "stdio.h"
char * strcat(char *s1,char *s2)
{
int i=0,j=0;
char *p=s1,*q=s2;
while(*p++)i++;
while(*q++)s1[i++]=s2[j++];
return s1;
}
void main()
{
char a[20]="abc";
char b[10]="defg";
printf("%s\n",strcat(a,b));
}