将两个字符串连接起来，不要用strcat

#include <stdio.h>  

int main()  
{  
	char s1[80], s2[40];
	int i = 0, j = 0;
	printf("\ninput string1:");
	scanf("%s", s1);
	printf("\ninput string2:");
	scanf("%s", s2);
	while(s1[i] != '\0')
		i++;
	while(s2[j] != '\0')
		s1[i++] = s2[j++];
	s1[i] = '\0';
	printf("The new string is:%s\n", s1);
	return 0;  
}