求大神帮助，在VC++6.0 如何让用户选择加减乘除

#include
int main()
{
int a,b;
float result;

  printf("input one integer: ");
  scanf("%f",&a);
  printf("input another integer: ");
  scanf("%f",&b);

  result=a+b;
  printf("a+b=%.1d\n",result);

  result=a-b;
  printf("a-b=%.1d\n",result);

  result=a*b;
  printf("a*b=%.1f\n",result);

  result=a/b;
  printf("a/b=%.1f\n",result);

  return 0;

}

 char c;
scanf("%c", &c);
switch (c)
{
case '+':
result=a+b;
printf("a+b=%.1d\n",result);
break;
case '-':
...
}