找规律模拟（非原地算法）

#include <iostream>
#include <vector>

using namespace std;
int m, n;

int main(int argc, char** argv) {
  cin >> m >> n;
  vector<vector<int>> grid(m, vector<int>(n));
  for (int y = 0; y < m; ++y)
    for (int x = 0; x < n; ++x) cin >> grid[y][x];

  vector<vector<int>> matrix(n, vector<int>(m));
  for (int y = 0; y < m; ++y)
    for (int x = 0; x < n; ++x)
      matrix[x][m - 1 - y] = grid[y][x];

  for (int y = 0; y < n; ++y) {
    for (int x = 0; x < m; ++x)
      cout << matrix[y][x] << ' ';
    cout << endl;
  }

  return 0;
}