leetcode/cpp/0048.cpp at master · xfmeng17/leetcode · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
class Solution {
public:
  void rotate(vector<vector<int>> &matrix) {
    int n = matrix.size();
    if (n <= 1) {
      return;
    }
    for (int level = 0; level <= n / 2 - 1; level++) {
      for (int start = level; start <= n - 2 - level; start++) {
        trans(matrix, n, level, start);
      }
    }
    return;
  }

  void trans(vector<vector<int>> &matrix, int n, int i, int j) {
    int element = matrix[i][j];
    int ni = j;
    int nj = n - 1 - i;
    while (ni != i || nj != j) {
      int t = matrix[ni][nj];
      matrix[ni][nj] = element;
      element = t;
      int ti = ni;
      int tj = nj;
      ni = tj;
      nj = n - 1 - ti;
    }
    matrix[i][j] = element;
    return;
  }
};