LeetCode Q54: 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].

	class Solution {
	public:
	vector<int> spiralOrder(vector<vector<int>>& matrix) {
	vector<int> result;
	if(matrix.empty())
	return result;
	int m=matrix.size();
	int n=matrix[0].size();
	int u=n, r=m, d=n, l=m;
	int row=0, col=0;
	while(true){
	if(u==0)
	return result;
	int t=col+u;
	for(;col<t; col++){
	result.push_back(matrix[row][col]);
	}
	col--; r--; l--; row++;
	if(r==0)
	return result;
	t=row+r;
	for(;row<t; row++){
	result.push_back(matrix[row][col]);
	}
	row--; d--; u--; col--;
	if(d==0)
	return result;
	t=col-(d-1);
	for(;col>=t; col--){
	result.push_back(matrix[row][col]);
	}
	col++; l--; r--; row--;
	if(l==0)
	return result;
	t=row-(l-1);
	for(;row>=t; row--){
	result.push_back(matrix[row][col]);
	}
	row++; u--; d--; col++;
	}
	}
	};

view raw Q54SpiralMatrix.cpp hosted with ❤ by GitHub