Leetcode54——Spiral Matrix

文章作者：Tyan
博客：noahsnail.com  |  CSDN  |  简书

1. Description

2. Solution

class Solution {
public:
    vector<int> spiralOrder(vector<vector<int>>& matrix) {
        vector<int> result;
        int rows = matrix.size();
        if(rows == 0) {
            return result;
        }
        int columns = matrix[0].size();
        int total = rows * columns;
        for(int i = 0, j = 0; result.size() < total; i++, j++) {
            if(result.size() < total) {
                // top
                for(int k = j; k < columns - j; k++) {
                    result.push_back(matrix[i][k]);
                }
            }
            if(result.size() < total) {
                // right
                for(int k = i + 1; k < rows - i; k++) {
                    result.push_back(matrix[k][columns - 1 - j]);
                }
            }
            if(result.size() < total) {
                // bottom
                for(int k = columns - 2 - j; k >= j; k--) {
                    result.push_back(matrix[rows - 1 - i][k]);
                }
            }
            if(result.size() < total) {
                // left
                for(int k = rows - 2 - i; k > i; k--) {
                    result.push_back(matrix[k][j]);
                }
            }
        }
        return result;
    }
};

Reference

1. https://leetcode.com/problems/spiral-matrix/description/