Question

我正在做作业，并试图编写代码来回答这个问题：

编写一个计算货物总重量的程序。用户具有许多类型的框（编号从1到n）。对于每种盒子类型，程序都会询问用户重量和数量。然后程序计算并打印总货物重量。在下面的输出示例中，用户具有三种框类型。对于框类型2，用户输入前哨-1到表示输入已完成。您的程序应打印Type 1、2、3等，如输出如下。

Enter weight (lbs) of Type 1 box: 4
Enter quantity: 2
Enter weight (lbs) of Type 2 box: -1 
The total weight is 8 lbs.

当我运行此代码时，它将运行第一行以输入权重，但随后给我一个分段错误并说（核心已转储）。 -1是前哨，即使输入权重在while循环内，结果也相同。我究竟做错了什么？对不起，我是C的新手。

#include <stdio.h>

int main()
{
    int weight; //weight of boxes
    int quantity; //number of boxes 
    int total_weight; //total weight
    int n = 1;

    printf("Enter weight (lbs) of Type %d box: ", n);
    scanf("%d", weight);
    while(weight!=-1) //Iterate loop until w=-1 
    {
        printf("Enter quantity: \n");
        scanf("%d", quantity);

        total_weight= total_weight + (quantity*weight);
        n++;
    }

    printf("The total weight is %0.2d", total_weight);
    return 0;


}

Answer 1

这不是您使用scanf

的方式

scanf("%d", weight);
scanf("%d", quantity);

您应该传递变量的地址，而不是变量的值。

它看起来像这样：

scanf("%d", &weight);
scanf("%d", &quantity);

您的while循环取决于值weight。 weight的值永远不会在循环中更改，因此循环永远不会退出。

此行：

total_weight= total_weight + (quantity*weight);

使用从未初始化的total_weight值。
您应该初始化变量。

总而言之，我认为您的固定代码应如下所示：

#include <stdio.h>

int main()
{
    int weight       = 0; //weight of boxes
    int quantity     = 0; //number of boxes 
    int total_weight = 0; //total weight
    int n            = 1;

    while(weight!=-1)
    {
        printf("Enter weight (lbs) of Type %d box: ", n);
        scanf("%d", &weight);        // Update weight **inside** the loop
        printf("Enter quantity: \n");
        scanf("%d", &quantity);

        total_weight= total_weight + (quantity*weight);
        n++;
    }

    printf("The total weight is %0.2d", total_weight);
    return 0;
}

Answer 2

while(weight!=-1) //Iterate loop until w=-1 
{
printf("Enter quantity: \n");
scanf("%d", quantity);

total_weight= total_weight + (quantity*weight);
n++;
}

问题处于条件状态，权重永远不会改变其值，因此条件始终为true，因此会无限循环。

修正此声明scanf("%d", &weight);

Answer 3

您的问题是，您尝试为quantity和weight的指针分配一个值，相反，您需要放入&quantity和&weight，而您没有权重的另一个输入，您还应该使用do while代替while循环。看起来应该像这样

#include <stdio.h>

int main()
{
int weight; //weight of boxes
int quantity; //number of boxes 
int total_weight; //total weight
int n = 1;
    do
    {
    printf("Enter weight (lbs) of Type %d box: ", n);
    scanf("%d", &weight);
    printf("Enter quantity: \n");
    scanf("%d", &quantity);

    total_weight= total_weight + (quantity*weight);
    n++;
}while (weight != -1);

printf("The total weight is %0.2d", total_weight);
return 0;

}

如何修复c中while循环的分段错误

3 个答案: