Write a function which receives a pointer to the amount of money in
your pocket and the price of a bus ticket. Function decrements
the amount of money by the price of a bus ticket only if you have
enough money. If you had enough money function returns non-zero value
and zero if you did not have enough money. The amount of money shall not
decremented if you don't have enough money.

Write a main program that uses this function.


#include <stdio.h>
#include <stdlib.h>

int buy_a_ticket( float *cash, float price )
{
  *cash -= price;
  if (cash > price)
  return 1;
  else
  return 0;
}

int main()
{
  float pocket=20.0, price=0.25;
  printf( "my cash = $%.2f\n", pocket );
  printf( "buy a tickect at $%.2f\n", price );
  buy_a_ticket( &pocket, price );
  printf( "cash remaining = $%.2f\n", pocket );
  return 0;
}
不太对，请教应该怎么改，题目也不是很明白，难道要分别提问口袋里和车票有多少钱?

这样改才符合题意吧!

#include <stdio.h>
#include <stdlib.h>
int buy_a_ticket( float *cash, float price )
{
    if (*cash >= price)
    {
        *cash -= price;
        return 1;
    }
    else
        return 0;
}
int main()
{
    float pocket=20.0, price=0.25;
    printf( "my cash = $%.2f\n", pocket );
    printf( "buy a tickect at $%.2f\n", price );
    buy_a_ticket( &pocket, price );
    printf( "cash remaining = $%.2f\n", pocket );
    return 0;
}

[ 本帖最后由 cnfarer 于 2010-2-28 08:46 编辑 ]