输入一个矩阵，按照从外向里以顺时针的顺序依次打印出每一个数字，例如，如果输入如下矩阵： 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 则依次打印出数字1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10.

 

 

class Solution {public:    vector
     
       printMatrix(vector
      
       
         > matrix) {        int row = matrix.size();        int col = matrix[0].size();        vector
        
          res;                 // 输入的二维数组非法，返回空的数组        if (row == 0 || col == 0)  return res;                 // 定义四个关键变量，表示左上和右下的打印范围        int left = 0, top = 0, right = col - 1, bottom = row - 1;        while (left <= right && top <= bottom)        {            // left to right            for (int i = left; i <= right; ++i)  res.push_back(matrix[top][i]);            // top to bottom            for (int i = top + 1; i <= bottom; ++i)  res.push_back(matrix[i][right]);            // right to left            if (top != bottom)            for (int i = right - 1; i >= left; --i)  res.push_back(matrix[bottom][i]);            // bottom to top            if (left != right)            for (int i = bottom - 1; i > top; --i)  res.push_back(matrix[i][left]);            left++,top++,right--,bottom--;        }        return res;    }};
        
       
      
     

---

#include 
     
      #include 
      
       using namespace std;void PrintMatrix(vector 
       
        
         >& vec) {    int row = vec.size();    int col = vec[0].size();    int start = 0;    int num = 0;    while (start*2 < col && start*2 < row) {        int endx = col - start - 1;        int endy = row - start - 1;        for (int i = start; i <=endx; i++)            vec[start][i] = ++num;        if (start < endy) {            for (int i = start + 1; i <= endy; i++)                vec[i][endx] = ++num;        }        if (start < endx&&start < endy) {            for (int i = endx-1; i >= start; i--)                vec[endy][i] = ++num;        }        if (start < endx&&start < endy - 1) {            for (int i = endy - 1; i > start; i--)                vec[i][start] = ++num;        }        start++;    }    return;}int main() {    int num;    cin >> num;    vector
         
          
           > vec1(num, vector
           
            (num, 0)); PrintMatrix(vec1); for (int i = 0; i < num; i++) for (int j = 0; j < num; j++) cout<< vec1[i][j]<<" "; return 0;}