CS50 PSET1 贪婪 - 分配错误并使用模 (C)

Question

编译此代码时出现错误。 Z 是找零所需的最终硬币数量，目标是使用最少数量的硬币。我在顶部附近定义了int Z = 0。我尝试再次添加 int z 并将 print 语句中的类型更改为 f 但没有成功。

错误如下:

error: format specifies type 'int' but the argument has type '<dependent type>' [-Werror,-Wformat]
greedy.c:77:16: error: use of undeclared identifier 'z'
printf("%i\n", z);

这是我的代码。我是一个初学者，所以欢迎任何建议或更正。

#include <stdio.h>
#include <cs50.h>
#include <math.h>

int main(void)
{
    //prompt user for amount of change owed

    float f;
    int num; //amount of change

    do
    {
        printf("O hai! How much change is owed?:\n");
        f = get_float();
    }
    while (f < 0);   //verify input is positive

    num = round(f * 100); //rounds float

    //commence making change

    do{

        int c, e, i, j;

        int z = 0;   //z = coins

        if (num % 25 == 0)   // verifies that num is divisible by 25 so only 25c coins necessary
        {
            z = (num/25) + z; // updates final number of 25c coins
        }
        else if (num % 25 > 0)
        {

            i = num / 25;
            j = num % 25;

        }

        else if ((num / 25 < 0) || (num >=10 && num < 25))  //this means that f is less than 25 cents so has to be divided by 10 cent coins
        {

            num = c; 
            c = j + c;  //add remainder of num to the number to start with 
        }

        if (c % 10 == 0) // c is less than 25c but divisible by 10c pieces
        {
            z = (c / 10) + z;   //d is the final number of 10c coins

        }

        else if (c /10 < 1) //this means it's less than 10c
        {
            c = e;  // Then c must be less than 10c 
        }

        else if (e % 5 == 0) // divisible by 5c pieces
        {
            z = (e / 5) + z; // g is the number of 5 cent pieces

        }

        else if (e % 5 < 0) 
        {
        z = (e / 1) + z;  //h is the number of pennies        
        }

    }
    while (num > 0); //num is rounded float

    printf("%i\n", z);
}

Answer 1

首先，我建议您应该使用缩进正确格式化代码。

然后，错误的原因是 z 在与 do 循环和 printf("%i\n", z) 关联的 block 内声明; 超出了其范围。要消除此错误，请在 printf() 调用中可见的位置声明 z - 例如，在 do 之前循环。

请注意，声明 int Z = 0 不起作用，因为标识符的名称在 C 中区分大小写。