Question

当我测试轮盘赌机器人模拟器时，发生了一个奇怪的问题。该计划非常简单，并使用带轮盘赌的投注站点的机会。它有一个自动系统，可以自动为您下注，以便找到我做这个程序的最佳设置，但遇到了前所未有的问题ID。当试验数低于约400时，在计算百分比时会出错。

#include "stdafx.h"
#include <iostream>
#include <conio.h>
#include <Windows.h>
#include <cstdlib>
#include <ctime>
using namespace std;
int main()
{
    cout << "how many trials would you like?" << endl;
    HANDLE h = GetStdHandle(STD_OUTPUT_HANDLE);
    srand(time(0));
    double yAmount = 0;
    double bAmount = 0;
    double rAmount = 0;
    double gAmount = 0;
    int finaltrial = 0;
    int yellow = 1;
    int blue = yellow + 10;
    int red = blue + 17;
    int grey = red + 26;
    int money = 5000;
    int trialno = 0;
    int trials;
    cin >> trials;
    int result;
    int bet = 10;
    int moneyhigh = 0;
    bool win;
    bool bankrupt = false;
    while (trialno < trials || trials == 0 && bankrupt == true)
    {
        result = rand() % 54 + 1;
        if (result == yellow)
        {
            SetConsoleTextAttribute(h, FOREGROUND_RED | FOREGROUND_GREEN);
            cout << "Yellow";
            yAmount++;
            win = false;
        }
        else if (result <= blue)
        {
            SetConsoleTextAttribute(h, FOREGROUND_BLUE);
            cout << "Blue";
            win = false;
            bAmount++;
        }
        else if (result <= red)
        {
            SetConsoleTextAttribute(h, FOREGROUND_RED);
            cout << "Red";
            win = false;
            rAmount++;
        }    
        else if (result <= grey)
        {
            SetConsoleTextAttribute(h, FOREGROUND_GREEN);
            cout << "Green";
            win = true;
            gAmount++;
        }    
        if (win == true)
        {
            money = money + bet;
            bet = 10;
        }
        else
        {
            money = money - bet;
            bet = bet * 2;
        }
        if (bet > money)
        {
            finaltrial = trialno;
            trialno = trials - 1;
            bankrupt = true;
        }
        if (money > moneyhigh)
        {
            moneyhigh = money;
        }
        cout << endl << " trial: " << trialno << " money: " << money <<              endl;
        trialno++;
    }
    gAmount = gAmount / finaltrial ;
    rAmount = rAmount / finaltrial ;
    bAmount = bAmount / finaltrial ;
    yAmount = yAmount / finaltrial ;
    cout << endl << "Final: " << money << " Peak: " << moneyhigh << endl;
    cout << "Green: " << gAmount << "% " << "Red: " << rAmount << "% " <<     "Blue: " << bAmount << "% " << "Yellow: " << yAmount << "% " << endl;
    cin >> money;
    return 0;
}

Answer 1

在循环之前，用0初始化finaltrial。仅在if (bet > money)子句中编辑变量，这意味着如果语句永远不为真，则在循环结束时{{1 }将等于0，但是您将结果变量除以finaltrial，finaltrial定义为double，gAmount返回double / 0

Answer 2

在C或C ++中，如果将double数据类型除以0，则返回inf。您的变量 finaltrial 仅在 if（bet＆gt; money）返回 true时才会更新。当此条件失败时， finaltrial 保持为0， inf 会在这种情况下产生问题。

Answer 3

您可能希望将finaltrial初始化为1.

您已在程序开头将其初始化为0，然后在满足特定条件时更新它。无论是否满足巡视条件，您都在分区操作中使用finaltrial。当您进行除法操作时，您必须确保没有除0，否则您将获得inf。将finaltrial初始化为1可帮助您消除获取inf的问题（除非您将finaltrial的值更新为0）

Answer 4

获得+ inf的唯一方法是使用正分子将浮点除以零。知道这将有助于你像兔子一样捕捉这个问题。（注意，负分子除以零给出-Inf和0.0 / 0将评估为NaN - 而不是数字。）

显然，finalTrial为零，因为你只在最小的程序控制路径上改变它的值，所以这并不奇怪。

计算百分比c ++

4 个答案: