Question

我试图建立一个彩票游戏，该彩票游戏要求用户3次输入并将其与随机数组绘制的数字进行比较。如果这些用户号码中的任何一个与数组中的数字匹配，则程序应打印出匹配的数字。

ive试图在我的主要功能中使用while循环来控制流程，但即时通讯仍存在编译问题

#include<iostream>
#include <ctime>
#include "array.h"

using std::cout; using std::cin; using std::endl;
const int sizeofArray = 20;

void assign(int wins[], int sizeofArray);
void draw(int sizeofArray, int wins[]);
bool check(int num1, int wins[], int sizeofArray);
void entry(int& userNum);
void printOut(int wins[], int num);


int main() {

    srand(time(nullptr));
    int user[sizeofArray];
    cout << "Good luck with this weeks lotto drawing!" << endl;
    int wins[sizeofArray];

    assign(wins, sizeofArray);
    draw(sizeofArray, wins);
    int userInput;
    entry(userInput);

   bool win = check(userInput, wins, sizeofArray);
    if (win)
        cout << "you have won!" << endl;
    printOut(wins, sizeofArray);

}


void assign(int wins[], int sizeofArray) {
    for (int i = 0; i < sizeofArray; ++i)
        wins[i] = 0;
}
void draw(int sizeofArray, int wins[]) {
    int number = 0;
    while (number < sizeofArray) {
        int number = rand() % 100 + 1;
        if (!check(number, wins, sizeofArray)) {
            wins[number] = number;
            number++;
        }
    }
}
bool check(int num1, int wins[], int sizeofArray) {
    for (int j = 0; j < sizeofArray; j++) {
        if (wins[j] == num1)
            return true;
    }
    return false;
}
void entry(int& userNum) {
    int j;
    cout << "Enter your lottery number guess: ";
    cin >> userNum;
    cout << "Your number was " << userNum << endl;
}
void printOut(int wins[], int num) {
    cout << "Winning numbers in lottery are" << endl;
    for (int j = 0; j < num; ++j) {
        cout << wins[j] << " ";
    }
}

i

Answer 1

您的draw方法将无限循环，因为您两次声明了条件变量，这导致++运算符应用于错误的变量

void draw(int sizeofArray, int wins[]) {
    int number = 0; // <--- HERE
    while (number < sizeofArray) {
        int number = rand() % 100 + 1; // <--- AND HERE
        if (!check(number, wins, sizeofArray)) {
            wins[number] = number;
            number++; //This will increase the inner variable number not the outer one
        }
    }
}

要解决此问题，只需更改变量名

void draw(int sizeofArray, int wins[]) {
    int counter = 0; <---
    while (counter < sizeofArray) { <---
        int number = rand() % 100 + 1;
        if (!check(number, wins, sizeofArray)) {
            wins[number] = number;
            counter++; <---
        }
    }
}

Answer 2

让我们看一下draw()：

void draw(int sizeofArray, int wins[]) {
    int number = 0; //First variable of name number
    while (number < sizeofArray) {
        //new variable with name number is introduced, it shadows the first one  
        int number = rand() % 100 + 1; //<-----------------------+
        if (!check(number, wins, sizeofArray)) {              // |
            wins[number] = number;                            // |
            number++; //Here you actually increase this variable-+
        }
    }
}

所谓的阴影在这里发生，并且外部int number永远不会在循环内部被修改。只需重命名其中之一，就可以了。

如果您想了解更多有关此内容的信息，请查看here。

尝试制作乐透游戏，执行和编译时遇到问题

2 个答案: