Spiral Matrix

Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.

For example,
Given the following matrix:

[
 [ 1, 2, 3 ],
 [ 4, 5, 6 ],
 [ 7, 8, 9 ]
]

You should return [1,2,3,6,9,8,7,4,5].

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 33 34 35 36 37 38 39 40 41 42 43 44

class Solution { public: vector<int> spiralOrder(vector<vector<int>>& matrix) { vector<int> result; int m = matrix.size(); if(m == 0){ return result; } int n = matrix[0].size(); int dir = 0; int top = 0, bottom = m - 1, left = 0, right = n - 1; while(top <= bottom && left <= right){ if(dir == 0){ for(int i = left; i <= right; i++){ result.push_back(matrix[top][i]); } top++; dir = 1; } else if(dir == 1){ for(int i = top; i <= bottom; i++){ result.push_back(matrix[i][right]); } right--; dir = 2; } else if(dir == 2){ for(int i = right; i >= left; i--){ result.push_back(matrix[bottom][i]); } bottom--; dir = 3; }else{ for(int i = bottom; i >= top; i--){ result.push_back(matrix[i][left]); } left++; dir = 0; } } return result; } };