BMI
身体质量指数（BMI，Body Mass Index）是国际上常用的衡量人体肥胖程度和是否健康的重要标准，主要用于统计分析。肥胖程度的判断不能采用体重的绝对值，它天然与身高有关。因此，BMI 通过人体体重和身高两个数值获得相对客观的参数，并用这个参数所处范围衡量身体质量。
计算公式
体重指数BMI=体重/身高的平方（国际单位kg/㎡）
理想BMI(18.5～23.9) = 体重(单位Kg) ÷ 身高的平方 (单位m)根据世界卫生组织定下的标准，亚洲人的BMI（体重指标Body Mass Index)若高于22.9便属于过重。亚洲人和欧美人属于不同人种，WHO的标准不是非常适合中国人的情况，为此制定了中国参考标准：
来源：百度百科
程序可以这么写，先创建两个个文本文档:AldBMI.txt
里面写：
low 0 18.4
right 18.5 23.9
big 24.0 27.9
large 28.0 100.0
和StuBMI.txt
low 10.0 14.6
right 14.7 21.8
big 21.9 24.5
large 24.8 100.0
代表学生版和成人版BMI数据
我们把下限设为0，上限设为100，这样以免麻烦
代码：
#include <iostream>
#include <string>
#include <fstream>
#include <conio.h>
#include <iomanip>
#include "windows.h"
using namespace std;
void OUTlevel(string s)
{
if(s == "low")
cout << "您的BMI等级为:" << "偏瘦" << endl;
else if(s == "big")
cout << "您的BMI等级为:" << "超重" << endl;
else if(s == "large")
cout << "您的BMI等级为:" << "肥胖" << endl;
}
void CheckAndOut(double AnsBMI, double high, double weight)//最后检查输出
{
const double rightWeightB = 21.8 * (high * high);//常量定义，正常重量边界
const double rightWeightS = 14.7 * (high * high);//常量定义，正常重量边界
if(rightWeightS > AnsBMI)
cout << "您还需要加" << rightWeightS - AnsBMI << "Kg" << endl;
else if(rightWeightB < AnsBMI)
cout << "您还需要减" << AnsBMI - rightWeightB << "Kg" << endl;
}
struct BMI_ALL{//结构体定义，
string lv;//等级
double score_small;//小成绩
double score_big;//大成绩
};
void BMI_STUDENT();
void BMI_ALDULT();//提前声明
void BMI_m()//menu主界面
{
while(true){
cout << "--------BMI test--------" << endl;
cout << "aldult [1]" << endl;
cout << "student [2]" << endl;
cout << "exit [0]" << endl;
cout << "------------------------" << endl;
cout << ">>> ";
int Choose;
cin >> Choose;//无等待输入-conio.h
switch (Choose)
{
case 1:
system("cls");
BMI_ALDULT();
break;
case 2:
system("cls");
BMI_STUDENT();
break;
case 0:
goto loop;
}
}
loop:
return;
}
void BMI_STUDENT()
{
ifstream fin("StuBMI.txt");
double high, weight;
cout << "BMI for aldult:" << endl;
cout << "tips:输入时如无小数点加.0" << endl;
cout << "input your high(M)" << endl;
cin >> high;
cout << "input your weight(kg)" << endl;
cin >> weight;
double BMIn = weight / (high * high);//19.65
BMI_ALL student[4];
for(int i = 0; i < 3; i++){
fin >> student[i].lv >> student[i].score_small >> student[i].score_big;//录入等级
}/*
for(int i = 0; i < 3; i++){
cout << student[i].lv << student[i].score_small << student[i].score_big << endl;
}*/
for(int i = 0; i < 3; i++)
if(BMIn >= student[i].score_small && BMIn <= student[i].score_big){
cout << "BMI值=" << BMIn << endl;
OUTlevel(student[i].lv);
if(i == 1)
cout << "恭喜！达到正常水平！" << endl;//是否达到正常水平
else
CheckAndOut(BMIn, high, weight);//否则不正常-二阶查看
//cout << "check loop" << endl;
}
//cout << "check loop" << endl;
system("pause");
system("cls");
return;
}
void BMI_ALDULT()
{
ifstream fin("AldBMI.txt");
double high, weight;
cout << "BMI for aldult:" << endl;
cout << "tips:输入时如无小数点加.0" << endl;
cout << "input your high(M)" << endl;
cin >> high;
cout << "input your weight(kg)" << endl;
cin >> weight;
double BMIn = weight / (high * high);//19.65
BMI_ALL student[4];
for(int i = 0; i < 3; i++){
fin >> student[i].lv >> student[i].score_small >> student[i].score_big;//录入等级
}/*
for(int i = 0; i < 3; i++){
cout << student[i].lv << student[i].score_small << student[i].score_big << endl;
}*/
for(int i = 0; i < 3; i++)
if(BMIn >= student[i].score_small && BMIn <= student[i].score_big){
cout << "BMI值=" << BMIn << endl;
OUTlevel(student[i].lv);
if(i == 1)
cout << "恭喜！达到正常水平！" << endl;//是否达到正常水平
else
CheckAndOut(BMIn, high, weight);//否则不正常-二阶查看
//cout << "check loop" << endl;
}
//cout << "check loop" << endl;
system("pause");
system("cls");
return;
}
int main()
{
BMI_m();
return 0;
}
详细文件、代码、exe文件链接：
https://download.csdn.net/download/cool99781/12149691