CS50 pset1 的奇怪总和值 - 贪心挑战

Question

我已经在 PSET1 的 CS50 中完成了贪婪挑战的代码

不过，硬币的总数returns相当多。当我进一步查看时，我的镍币数量似乎很大（4381344 个硬币换 0.48 美分）。

叫我傻瓜，但我已经为此烦恼了一段时间。谁能指出原因？

#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

您忘记初始化变量。变化：

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

进入：

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 没有被初始化，然后它开始等于存储它的内存中已经存在的任何垃圾。

然后来到这部分的时候，并没有得到新的值，因为money小于nickels:

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

因此它从来没有被分配一个新值而不是它开始时的垃圾。

从中得到的教训：始终初始化变量。

CS50 pset1 的奇怪总和值 - 贪心挑战

Weird sum value for CS50 pset1- Greedy challenge

c

cs50