順時針打印矩陣

題目描述

輸入一個矩陣，按照從外向裏以順時針的順序依次打印出每一個數字，例如，如果輸入如下4 X 4矩陣： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 則依次打印出數字1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10.

 

模擬過程，注意細節

 

  class Solution
  {
    public:
      vector<int> printMatrix(vector<vector<int>> matrix)
      {
          int row1 = 0, row2 = matrix.size() - 1;
          if (matrix.size() == 0)
              return {};
          int col1 = 0, col2 = matrix[0].size() - 1;
          vector<int> ans;
          //0正序 往左或者往下
          int cntRow = 0;
          int cntCol = 0;
          //0水平方向輸出
          int turn = 0;
          while (row1 <= row2 && col1 <= col2)
          {
              if (turn == 0)
              {
                  turn = 1;
                  if (cntRow == 0)
                  {
                      cntRow = 1;
                      for (int i = col1; i <= col2; ++i)
                          ans.push_back(matrix[row1][i]);
                      ++row1;
                  }
                  else
                  {
                      cntRow = 0;
                      for (int i = col2; i >= col1; --i)
                          ans.push_back(matrix[row2][i]);
                      --row2;
                  }
              }
              else
              {
                  turn = 0;
                  if (cntCol == 0)
                  {
                      cntCol = 1;
                      for (int i = row1; i <= row2; ++i)
                          ans.push_back(matrix[i][col2]);
                      --col2;
                  }
                  else
                  {
                      cntCol = 0;
                      for (int i = row2; i >= row1; --i)
                          ans.push_back(matrix[i][col1]);
                      ++col1;
                  }
              }
          }
          return ans;
      }
  };