BMI分类结构

Question

我正在做一项C语言的作业，我必须读取多个人的身高和体重，并确定他们的bmi。然后我将它们归入各自的bmi类别，但我被困在如何正确地做到这一点上，这是我到目前为止的代码：

# include <stdio.h>

int main () {

    int people;
    double bmi, weight, inches;

            printf("How many peoples? > ");
            scanf("%d", &people);

    do {
            printf("Enter height (inches) and weight (lbs) (%d left) > ", people);
            scanf("%lf %lf", &inches, &weight);
            people--;
    }

    while (people > 0);

            bmi = (weight / (inches * inches)) * 703;

            if (bmi < 18.5) {
                    printf("Under weight: %d\n", people);
            }
            else if (bmi >= 18.5 && bmi < 25) {
                    printf("Normal weight: %d\n", people);
            }
            else if (bmi >= 25 && bmi < 30) {
                    printf("Over weight: %d\n", people);
            }
            else if (bmi >= 30) {
                    printf("Obese: %d\n", people);
            }
return 0;
}

我哪里错了？我该在哪里修复这段代码？

Answer 1

使用一些数据结构来存储数据。您正在获取多个人的输入，但最终为一个人处理。

而且people--;也完成了。因此BMI变量递减到零，这使得while退出而不执行people计算。

修改代码：

#include <stdio.h>

#define MAX_PEOPLE      100

int main () {

    int people;
    double bmi[MAX_PEOPLE], weight[MAX_PEOPLE], inches[MAX_PEOPLE];

    int index = 0;

            printf("How many peoples? > ");
            scanf("%d", &people);

    index = people;

    do {
            printf("Enter height (inches) and weight (lbs) (%d left) > ", index);
            scanf("%lf %lf", &inches[index], &weight[index]);
            index--;
    }while (index > 0);

        for(index = 0; index < people; index++)
        {

            bmi[index] = (weight[index] / (inches[index] * inches[index])) * 703;

            if (bmi[index] < 18.5) {
                    printf("Under weight: %d\n", index);
            }
            else if (bmi[index] >= 18.5 && bmi[index] < 25) {
                    printf("Normal weight: %d\n", index);
            }
            else if (bmi[index] >= 25 && bmi[index] < 30) {
                    printf("Over weight: %d\n", index);
            }
            else if (bmi[index] >= 30) {
                    printf("Obese: %d\n", index);
            }
        }
return 0;
}

Answer 2

现在，您正在处理相同的数据。

每次指定新的值来加权时，旧的值都会被删除。

您可以像这样创建多个变量：

double weight1, weight2, weight3, weight4, ...etc (非常不切实际！！)或者创建一个双精度数组：

double weight[100]; 

并像这样引用每个特定的双精度变量：

scanf("%lf %lf", inches[0], weight[0]);
scanf("%lf %lf", inches[1], weight[1]);
scanf("%lf %lf", inches[2], weight[2]);

你明白我的意思了吗？您可以通过for循环来操作数组。