循环中的空间计算量

Question

我用C++制作了一个程序，画出一棵圣诞树，但是我对树桩有一些问题。我真的不明白为什么它不想出现在中间(与树的顶端一致，使整个树对称)。

我有嵌套的循环，但是，我计算正确的空格吗？

以下是我到目前为止在代码方面所做的工作：

int treeHeight;

int main()
{
    cout << "Enter the size of the tree (4-20): ";
    cin >> treeHeight;

    void getValidHeight();
    getValidHeight();

    // Set tree height to 2 lower than it is (part of spec I'm following)
    treeHeight = treeHeight - 2;

    // Set tree character 
    char leaf = '#';

    // Set tree stump character 
    char treeStump = '|';

    // First leaf (top of tree)
    int leaves = 1;

    int treeWidth = treeHeight / 2;

    int stumpHeight = 2;

    for (int total = treeHeight; total > 0; --total)
    {
        //control the amount of spaces
        for (int i = (total - 1); i > 0; --i)
            cout << " ";

        //control the amount of leaves
        for (int j = 0; j < leaves; ++j)
        {
                cout << leaf;
        }

        // Next row needs 2 extra leaves
        leaves += 2;

        cout << '\n';
    }

    // Create the stump
    for (int i = 0; i < stumpHeight; ++i)
    {
        // Spaces to the center of the tree so that the stump is centered
        for (int j = 0; j < treeWidth; ++j)
            cout << " ";

        for (int k = 0; k < 1; ++k)
            cout << treeStump;

        cout << '\n';
    }

    system("pause");
    return 0;
}

void getValidHeight()
{
    while (treeHeight > 20 || treeHeight < 4)
    {
        cout << "\nEROOR: Invalid height! Enter the size of the tree (4-20): ";
        cin >> treeHeight;
    }
}

Answer 1

因为你的树宽不是树高的一半！例如，尝试将宽度更改为

int treeWidth = treeHeight*2;

然后在后备箱前面写空格如下：

// Spaces to the center of the tree so that the stump is centered
for (int j = 0; j < treeWidth/2-1; ++j)
    cout << " ";

我还在树的最上面加了一条新的线。圣诞快乐！

                 #
                ###
               #####
              #######
             #########
            ###########
           #############
          ###############
         #################
        ###################
       #####################
      #######################
     #########################
    ###########################
   #############################
  ###############################
 #################################
###################################
                 |
                 |