Question

对于我的计算机编程课程，我决定制作一个程序，生成随机硬币翻转并跟踪头部和尾部最长的连续条纹。我搜索了互联网，没有找到答案。计数显示不正确。即使只是一个提示也会很棒！谢谢，贾斯汀

int main(){

    int number_of_flips;
    int coin_flip;
    int previous_flip = 2;
    int head_count = 0;
    int tail_count = 0;
    int highest_head = 0;
    int highest_tail = 0;

    srand(time(NULL));

    cout << "Enter the number of coin flips:" << endl;
    cin >> number_of_flips;
    system("cls");

    for(int i = 0; i < number_of_flips; i++){


        coin_flip = rand() % 2;

        if(coin_flip == 0){
            cout << "Heads" << endl;
            if(coin_flip == previous_flip){
                  head_count = head_count + 1;       
             }
             else{
                 if(head_count > highest_head){
                     highest_head = head_count;                  
                 }

                 head_count = 0;      
             }
        }

        if(coin_flip == 1){
            cout << "Tails" << endl;
            if(coin_flip == previous_flip){
                  tail_count = tail_count + 1;        
            }
            else{
                 if(tail_count > highest_tail){
                      highest_tail = tail_count;              
                 }

                 tail_count = 0;     
            }
        }


        previous_flip = coin_flip;
    }

    cout << "The longest run of heads is " << highest_head << endl;
    cout << "The longest run of tails is " << highest_tail << endl;

    system("pause");
    return 0;
}

以下是输出示例：

Tails
Tails
Tails
Heads
Heads
Tails
Tails
Tails
Tails
Heads
The longest run of heads is 1
The longest run of tails is 2

作为参考，这是我认为现在可以使用的最终代码：

int main(){

    int number_of_flips;
    int coin_flip;
    int previous_flip = 2;
    int head_count = 0;
    int tail_count = 0;
    int highest_head = 0;
    int highest_tail = 0;

    srand(time(NULL));

    cout << "Enter the number of coin flips:" << endl;
    cin >> number_of_flips;
    system("cls");

    for(int i = 0; i < number_of_flips; i++){


        coin_flip = rand() % 2;

        if(coin_flip == 0){
            cout << "Heads" << endl;
            if(coin_flip == previous_flip){
                  head_count = head_count + 1;       
             }
             else{
                 if(head_count > highest_head){
                     highest_head = head_count;                  
                 }

                 head_count = 1;      
             }
        }

        if(coin_flip == 1){
            cout << "Tails" << endl;
            if(coin_flip == previous_flip){
                  tail_count = tail_count + 1;        
            }
            else{
                 if(tail_count > highest_tail){
                      highest_tail = tail_count;              
                 }

                 tail_count = 1;     
            }
        }
        previous_flip = coin_flip;
    }
    if(head_count > highest_head){
           highest_head = head_count;              
    }
    if(tail_count > highest_tail){
           highest_tail = tail_count;              
    }
    cout << "The longest run of heads is " << highest_head << endl;
    cout << "The longest run of tails is " << highest_tail << endl;

    system("pause");
    return 0;
}

Answer 1

您的代码未考虑最后条纹，因为您只在 next 翻转时检查highest_head或highest_tail不同。在最后一次翻转时，没有下一次翻转。

由于这是作业，我将不会建议如何修复你的代码。

Answer 2

要添加到Greg答案，如果previous_flip被初始化为0（可能因为你没有明确地自己做，它也可能是其他任何东西，但通常在调试它是0）和你的第一个翻转是1，你的计数也将被关闭。

有一些错误，但我也不会发布代码。

首先，你永远不会计算与最后一个不同的第一个翻转。只有当前翻转等于最后一次翻转时，才会增加翻转计数。就在那里，你错过了一个。

然后，仅当当前翻转不等于最后一个时才设置最大条纹。然后发生的是你只能正确计算第一个条纹（假设你计算第一个右转），因为第二个条纹只有在它返回到同一个翻转时才会更新其最大条纹。以下是您提供的序列所发生的情况：

Tails   // Does not count this one because flip != last_flip
Tails   // tail_count is 1
Tails   // tail_count is 2
Heads   // Does not count first flip on flip switch, reset head_count to 0
Heads   // head_count is 1
Tails   // Does not count first flip, set max_tail to 2, reset tail_count to 0
Tails   // tail_count is 1
Tails   // tail_count is 2
Tails   // tail_count is 3 but will never be set unless we flip head, then tail.
Heads   // Does not count first switch, set max_head to 1, reset head_count to 0

现在修复该算法。

C ++跟踪最长的条纹

2 个答案: