C程序运行失败，求教什么原因

Question

#include "stdio.h"
#include
main()
{
char *s="abc";
int i,j;
char c;
for(i=0,j=strlen(s)-1;i<j;++i,--j)
{
c=s[i];
s[i]=s[j];
s[j]=c;
}
printf("%s\n",s);

}

Answer 1

#include "stdio.h"
#include "string.h"
void main()
{
char s[]="abc";
int i,j;
char c;
for(i=0,j=strlen(s)-1;i<j;++i,--j)
{
c=s[i];
s[i]=s[j];
s[j]=c;
}
printf("%s\n",s);

}
改了一下 看一下是不是这种效果