C程序在第一次输入时崩溃答案

【问题标题】：C program crashing upon first inputsC程序在第一次输入时崩溃
【发布时间】：2015-02-14 03:58:42
【问题描述】：

我遇到了一个 C 程序在第一次用户输入时崩溃的问题。我认为应该是对的；我遇到的问题是在没有给出错误的情况下正常运行，但是一旦你给出第一个输入，它就会立即崩溃。有什么想法吗？

# define DOUGH_PER_SQFT 0.75
# define INCHES_PER_FEET 12
# define PI 3.141592654

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

int main() {

    // Get user inputs.

    int small, medium, large;

    printf("What is the radius of your small pizza, in inches?\n");
    scanf("%d", small);
    printf("What is the radius of your medium pizza, in inches?\n");
    scanf("%d", medium);
    printf("What is the radius of your large pizza, in inches?\n");
    scanf("%d", large);

    int smallfeet, mediumfeet, largefeet;

    smallfeet = ("%d/12", small);
    mediumfeet = ("%d/12", medium);
    largefeet = ("%d/12", large);

    // Find the amount of dough, in pounds, that will need to be ordered

    int surface_small, surface_medium, surface_large;

    surface_small = (PI*pow(smallfeet,2));
    surface_medium = (PI*pow(mediumfeet,2));
    surface_large = (PI*pow(largefeet,2));

    int smallweight, medweight, largeweight, doughneeded;

    smallweight = surface_small*DOUGH_PER_SQFT;
    medweight = surface_medium*DOUGH_PER_SQFT;
    largeweight = surface_large*DOUGH_PER_SQFT;

    int dough_for_smalls, dough_for_mediums, dough_for_larges, dough_needed;

    dough_for_smalls = smallweight*small;
    dough_for_mediums = medweight*medium;
    dough_for_larges = largeweight*large;
    dough_needed = dough_for_smalls + dough_for_mediums + dough_for_larges;

    // Find the answer.

    printf("You will need to buy ",dough_needed,"pounds of dough for this week");

    return 0;

}

【问题讨论】：

诸如`smallfeet = ("%d/12", small)? And printf("You will need to purchase ",dough_needed,"数磅面团等语句背后的目的是什么？ ");` 不会打印dough_needed 的值。您真的应该阅读 C 书籍或教程。
我认为如果您坐下来阅读K&R，您会受益匪浅。它简短易读。

标签： c crash

【解决方案1】：

你需要传递scanf的变量地址

scanf("%d", &small);

其他类似

【讨论】：

哇。我真的很烂。你是最棒的
最后一件事 - 在这一点上，它接受用户输入的大小，但随后不执行任何计算。它直接进入最终的 printf，但由于它没有执行任何计算，所以它只是空白。
@JordanBarden 研究comma operator，每个地方你都用错了。编译时打开警告。

【解决方案2】：

改变

scanf("%d", small); //and
scanf("%d", medium); //and
scanf("%d", large);

到

scanf("%d", &small); //and
scanf("%d", &medium); //and
scanf("%d", &large);

这样做是因为scanf 中的%d 格式说明符需要int*，但您提供了导致崩溃的int。

代码中还有其他问题。要修复它们，请更改

smallfeet = ("%d/12", small);
mediumfeet = ("%d/12", medium);
largefeet = ("%d/12", large);

到

smallfeet = small/12;
mediumfeet = medium/12";
largefeet = large/12;

和

printf("You will need to buy ",dough_needed,"pounds of dough for this week");

到

printf("You will need to buy %d pounds of dough for this week",dough_needed);

【讨论】：