Question

我已经完成了PSET1＆＃39s中贪婪挑战的代码

但是，硬币返还的总数非常大。当我进一步研究它时，似乎我的镍币数量巨大（4381344硬币，0.48美分）。

叫我傻，但因此我一直在拉头发。任何人都可以指出为什么？

#include <cs50.h>
#include <stdio.h>
#include <math.h>
// You want to:
// get user input of a float
// check float
// Loop: minus money with biggest coins unit until negative
// then loop and loop
// until 1
// then count the number of loop (by assign a variable to count)
int main(void)
{
    float money_give; 
    int quarters= 25, qc, dimes = 10, dc, nickels= 5, nc,pennies= 1, pc;
    do
    {
    printf("O hai! How much change is owed?\n");
    money_give = get_float();
    }
    while (money_give <= 0.0);
    money_give = money_give * 100;
    int money = (int)round(money_give);
    while (money >= quarters)
    {
        qc = money / quarters;
        money = money % quarters;
    }
    while (money >= dimes)
    {
        dc = money / dimes;
        money = money % dimes;
    }
    while (money >= nickels)
    {
        nc = money / nickels;
        money = money % nickels;
    }
    while (money >= pennies)
    {
        pc = money / pennies;
        money = money % pennies;
    }
    printf("%i\n",pc+ nc+ qc +dc);
    printf("%i\n",nc);
    printf("%i\n",qc);
    printf("%i\n",dc);
    printf("%i\n",pc);
 }

哦，输出是：

O hai! How much change is owed?
0.48
4381350
4381344
1
2
3

Answer 1

您忘了初始化变量。变化：

int quarters= 25, qc, dimes = 10, dc, nickels= 5, nc,pennies= 1, pc;

成：

int quarters= 25, qc = 0, dimes = 10, dc = 0, nickels= 5, nc = 0, pennies= 1, pc = 0;

发生的事情是因为nc尚未初始化，所以它开始时等于存储它的内存中已有的垃圾。

然后当你来到这个部分时，它没有得到新值，因为money小于nickels：

    while (money >= nickels)
    {
        nc = money / nickels;
        money = money % nickels;
    }

因此，它永远不会被分配一个新值而不是它开始的垃圾。

从中得到的教训：始终初始化变量。

CS50 pset1-贪婪挑战的奇怪总和值

1 个答案: