C++ 猜谜游戏 : unable to get midpoint properly

Question

我在做一个示例练习时遇到了一些麻烦。

目标是让计算机通过反复取中点直到达到数字来猜测您的数字。我拥有一切，除了我似乎无法“降低”工作。

#include <iostream>
using namespace std;

void playOneGame();
bool shouldPlayAgain();
int getAverage(int min, int max);
int getLow(int min, int max);
int getHigh(int min, int max);
char getResponse();

const int MAX_VALUE = 100;
const int MIN_VALUE = 0;
int AVERAGE = 50;
char choice;
int high = MAX_VALUE;
int low = MIN_VALUE;

int main()
{
    do
    {
        playOneGame();
    } while (shouldPlayAgain());

    return 0;
}

void playOneGame()
{
    cout<<"Think of a number between " << MIN_VALUE << " and " << MAX_VALUE << endl;
    getAverage(MIN_VALUE, MAX_VALUE);
}

int getAverage(int min, int max)
{
    AVERAGE = (max - min)/2;
    getResponse();
}

int getHigh(int low, int max)
{
    low = AVERAGE;
    AVERAGE += ( high - low ) / 2;    
    getResponse();
}

int getLow(int low, int max)
{
    high = AVERAGE;
    AVERAGE -= (high - low) /2;
    getResponse();
}

char getResponse()
{
    cout << "Is it " << AVERAGE << " ?" << "  (h/l/c): " << endl;
    cin >> choice;
    if(choice == 'h' || choice == 'H') 
    {
        getHigh(low, high);
    }
    else if(choice == 'l' || choice == 'L') 
    {
        getLow(low, high);
    }
    else
    {
        cout<< "Got it!" <<endl;
    }
}

bool shouldPlayAgain()
{
    bool status;
    char choice;

    cout << "Do you want to play again? Y/N\n";
    cin >> choice;

    if(choice == 'y' || choice == 'Y')
        status = true;
    else
        status = false;

    return status;
}

#15 的示例输出如下:

Think of a number between 0 and 100Is it 50 ?  (h/l/c):  lIs it 25 ?  (h/l/c):  lIs it 13 ?  (h/l/c):  hIs it 19 ?  (h/l/c):  lIs it 10 ?  (h/l/c):  hIs it 14 ?  (h/l/c):  hIs it 16 ?  (h/l/c):  lIs it 8 ?  (h/l/c):  hIs it 12 ?  (h/l/c):  hIs it 14 ?  (h/l/c):  hIs it 15 ?  (h/l/c):  cGot it!Do you want to play again? Y/N

代替

Is it 25 ?  (h/l/c):  lIs it 13 ?  (h/l/c):  hIs it 19 ?  (h/l/c):  lIs it 10 ?  (h/l/c): 

应该是:

Is it 25 ?  (h/l/c):  lIs it 13 ?  (h/l/c):  hIs it 19 ?  (h/l/c):  lIs it 16 ?  (h/l/c): 

Answer 1

您的变量作用域有问题。

此处的变量“low”具有局部作用域。它使用传递给函数的值

int getHigh(int low, int max)
{
    low = AVERAGE;

赋值给low意味着赋给局部变量，而不是全局变量

此处的变量“high”具有全局范围。它使用此页面上任何位置分配的值

int getLow(int low, int max)
{
    high = AVERAGE;
    AVERAGE -= (high - low) /2;

另外，尝试使用函数的返回值。