这个该怎么写啊，求各位解疑

#include <stdio.h>
int main() {
 char s[2];
 int a,b;
 char c;
 scanf("%d%1s%d",&a,s,&b);
 c=s[0];
 printf("%d %d %c\n",a,b,c);
 printf("%d %d %d %d %d\n",a+b,a-b,a*b,a/b,a%b);
 printf("The ratio of %d versus %d is %.2f.\n",a,b,(float)a/b);
 printf("The ration of %d / %d is %.2f%%.\n",a,b,100.0f*a/b);
 return 0;
}