cs106x-lecture2(下)(Autumn 2017)

打卡cs106x(Autumn 2017)-lecture2

1、BMI

Write a complete C++ program with a main function to calculate 2 people's body mass index (BMI), using the following formula:

BMI = weight / height2 * 703

The BMI rating groups each person into one of the following four categories:

BMI	Category
below 18.5	class 1
18.5 - 24.9	class 2
25.0 - 29.9	class 3
30.0 and up	class 4

Match the following example output:

This program reads data for two people
and computes their body mass index (BMI).

Enter Person 1's information:
height (in inches)? 70.0
weight (in pounds)? 194.25
BMI = 27.8689, class 3

Enter Person 2's information:
height (in inches)? 62.5
weight (in pounds)? 130.5
BMI = 23.4858, class 2

BMI difference = 4.3831

You should break down your program into several functions, each of which helps solve the overall problem.

解答：

#include <iostream>
#include "console.h"
#include "simpio.h"

using namespace std;

void inputHeightAndWeight(double& h, double& w);
void calcuBmi(double& h, double& w, double& b);
void calcuClass(double& b, int& c);
void bmiDiff(double& b1, double& b2);
    
int main() {
    cout << "This program reads data for two people" << endl;
    cout << "and computes their body mass index (BMI)." << endl << endl;

    double h1, w1, b1, h2, w2, b2;
    int c1, c2;

    for (int i = 1; i < 3; i++) {
        cout << "Enter Person " << i << "'s information:" << endl;
        if (i == 1) {
            inputHeightAndWeight(h1, w1);
            calcuBmi(h1, w1, b1);
            calcuClass(b1, c1);
        } else {
            inputHeightAndWeight(h2, w2);
            calcuBmi(h2, w2, b2);
            calcuClass(b2, c2);
        }
    }
    bmiDiff(b1, b2);
    return 0;
}


void inputHeightAndWeight(double& h, double& w) {
    h = getDouble("height (in inches)? ");
    w = getDouble("weight (in pounds)? ");
}

void calcuBmi(double& h, double& w, double& b) {
    b = w / (h * h) * 703;
    cout << "BMI = " << b << ", ";
}

void calcuClass(double& b, int& c) {
    if (b < 18.5) {
        c = 1;
    } else if (b < 25.0) {
        c = 2;
    } else if (b < 30.0) {
        c = 3;
    } else {
        c = 4;
    }
    cout << "class " << c << endl << endl;
}

void bmiDiff(double& b1, double& b2) {
    cout << "BMI difference = ";
    if (b1 > b2) {
        cout << b1 - b2;
    } else{
        cout << b2 - b1;
    }
}

2、stringMysteryAB

What is the output of the following code?

解答：

marty steFOOppa

3、nameDiamond

Write a function named nameDiamond that accepts a string as a parameter and prints it in a "diamond" format as shown below. For example, the call of nameDiamond("MARTY"); should print:

M
MA
MAR
MART
MARTY
 ARTY
  RTY
   TY
    Y

解答：

#include <iostream>
#include <string>
#include "console.h"
#include "simpio.h"

using namespace std;

void nameDiamond(string s) {
    int len = s.length();

    // 上半部分
    for (int i = 0; i < len; i++) {
        cout << s.substr(0, i + 1) << endl;
    }

    // 下半部分
    for (int i = 1; i < len; i++) {

        // 空格
        for (int j = 0; j < i; j++) {
            cout << " ";
        }
        cout << s.substr(i, len - i) << endl;
    }
}

int main() {
    string name = getLine("Enter your name: ");
    nameDiamond(name);
    return 0;
}