Question

一道c语言题

Answer 1

#include "stdio.h"

void fun(char *p,char *q){

char ch;

while(ch=*p,*p=*q,*q=ch,*p && *q)

p++,q++;

if(*(p))

while(*++p=*++q);

else if(*(q))

while(*++q=*++p);

}

int main(int argc,char *argv[]){

char a[100],b[100];

FILE *fp;

printf("Enter 2 strings...\n");

scanf("%49s%49s",a,b);

printf("\nExchange before:\n%s\t%s\n",a,b);

fun(a,b);

printf("After the exchange:\n%s\t%s\n",a,b);

if((fp=fopen("d:\\student\\myout.txt","w"))==NULL){

printf("Failed to open the file, exit...\n");

return 0;

}

fprintf(fp,"%s %s\n",a,b);

fclose(fp);

return 0;

}

运行样例和代码图片：