C++ 抛硬币百分比

Question

我正在编写一个程序，该程序应该请求用户想要抛硬币的次数，然后计算抛出的正面(正面为 0，反面为 1)的百分比。但是，每次我输出代码时，我的代码总是给我 0% 的结果。这是我的代码:

#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

double percentHeads(int userTosses) {
    srand(4444);
    int tossChance = (rand() % 1);
    int heads = 0;
    double percentCalc = static_cast<double>(heads) / userTosses * 100;  

    for (int i = 1; i <= userTosses; i++) {
        if (tossChance == 0) {
            heads++;
        }
    }
    return percentCalc;
}

int main() {
    int userTosses;
    int tossPercent;
    cout << "Enter the number of times you want to toss the coin: ";
    cin >> userTosses;
    cout << endl;

    tossPercent = percentHeads(userTosses);
    cout << "Heads came up " << tossPercent << "% of the time." << endl;

    return 0;
}

Answer 1

您在错误的地方分配了变量。此外，如果您尝试测试 rand() 是否返回奇数，则需要对一个 (rand() & 1) 执行按位与操作。或者，如果您想查看它是否偶数，请对 2 取模 (rand() % 2)。

double percentHeads(int userTosses) {
    srand(4444);     // You should change this else you'll get same results
    int tossChance;
    int heads = 0;

    for (int i = 1; i <= userTosses; i++) {
        tossChance = rand() % 2;    // Move this here, and change to 2
        if (tossChance == 0) {
            heads++;
        }
    }
    // and move this here
    double percentCalc = static_cast<double>(heads) / userTosses * 100;  
    return percentCalc;
}