找到你想的数字的程序不能正常工作，有什么问题？

Question

我在处理这个递归代码时遇到了问题。 基本上，我希望计算机以尽可能少的步骤“猜测”我正在考虑的数字。 但是，除了最终输出之外，一切正常。 界限很好，它缩小了猜测范围，直到它问我我想到的数字是否是 16，如果我输入“=”，它应该输出 16 而它总是输出 50。有人能帮我找到错误吗？

#include <iostream>
#include <cmath>
#include <string>

using namespace std;

unsigned int search (unsigned int boundInf, unsigned int boundSup);

int main ()
{
    int b;
    b = search (1, 100);

    cout << "Your number must be : " << b << endl;
}

unsigned int search (unsigned int boundInf, unsigned int boundSup)
{
    string magnitude;
    int b;
    b = (boundSup + boundInf) / 2;
    
    cout << "Is your number <, > or = to " << b << "? ";
    cin >> magnitude;

    if (magnitude == "<") {
        cout << "Between " << boundInf << " and " << b << endl;
        search (boundInf, b);
    }
    else if (magnitude == ">") {
        cout << "Between " << b << " and " << boundSup << endl;
        search (b, boundSup);
    }
    
    return b;
}

Answer 1

您在深入研究递归函数时忘记更改b的值，这可以通过更改search函数轻松解决，如下所示：

unsigned int search(unsigned int boundInf, unsigned int boundSup)
{
    string magnitude;
    int b;
    b = (boundSup + boundInf) / 2;
    cout << "Is your number <, > or = to " << b << "? ";
    cin >> magnitude;

    if (magnitude == "<")
    {
        cout << "Between " << boundInf << " and " << b << endl;
        b = search(boundInf, b);
    }
    else if (magnitude == ">")
    {
        cout << "Between " << b << " and " << boundSup << endl;
        b = search(b, boundSup);
    }

    return b;
}