C ++试图计算用户输入特定数字的次数

Question

我正在尝试编写一个程序来计算用户从 while 循环中输入特定数字的次数。思路如下：

#include <iostream>
#include <ctime>
using namespace std;

int main() {
    bool progLoop = true;
    int Number;
    char response;
    while (progLoop == true)
    {
        cout << "Please enter a number: " << endl; \
        cin >> Number;
        cout << "Number collected!" << endl;
        cout << "Number of times that number has been entered: " << endl; //IDK how to do this part which is what I'm looking for.
        cout << "Do you want to enter another number?" << endl;
        cin >> response;
        if (response == 'y') 
        {
            progLoop == true;
        }
        else if(response == 'n')
        {
            progLoop == false;
        }
    }
}

我正在寻找一种方法来存储特定数字已输入程序的次数的值。如果有任何问题想澄清一下！谢谢！ （修改我的代码会很棒！）

Answer 1

将我的评论扩展为答案

这样做的一种方法是使用std::vector，每次输入新数字时，都会将其推回向量中。然后您可以在需要检查时std::count该号码。在你的程序中，它看起来像这样：

#include <iostream>
#include <vector>
#include <algorithm>
#include <ctime>
using std::cout;
using std::cin;
using std::endl;

int main() {
    bool progLoop = true;
    int Number;
    std::vector<int> numCount;
    char response;
    while (progLoop == true)
    {
        cout << "Please enter a number: " << endl;
        cin >> Number;
        numCount.push_back(Number);
        cout << "Number collected!" << endl;
        cout << "Number of times that number has been entered: " << std::count(numCount.begin(), numCount.end(), Number) << endl;
        cout << "Do you want to enter another number?" << endl;
        cin >> response;
        if (response == 'y') 
        {
            progLoop = true; // You accidentally used == here
        }
        else if(response == 'n')
        {
            progLoop = false; // You accidentally used == here
        }
    }
}

Answer 2

使用hashmap：

#include <unordered_map>
#include <iostream>
#include <ctime>
using namespace std;

int main() {
    int number;
    char response = 'y';
    unordered_map<int, int> m; // your hashmap

    while (response == 'y')
    {
        cout << "Please enter a number: " << endl; 
        cin >> number;
        cout << "Number collected!" << endl;
        cout << "Number of times that number has been entered: " << ++m[number] << endl; // preincrement your hashmap at key number
        cout << "Do you want to enter another number? (y/n)" << endl;
        cin >> response;
        response = tolower(response); // give a chance to exit the loop if your user like to use caplock (like Trump)
    }
}