[LeetCode]54번 : Spiral Matrix

문제 링크:leetcode.com/problems/spiral-matrix/

Spiral Matrix - LeetCode

접근 방식:

Given an m x n matrix, return all elements of the matrix in spiral order.

 

Example 1:

Input: matrix = [[1,2,3],[4,5,6],[7,8,9]] Output: [1,2,3,6,9,8,7,4,5]

Example 2:

Input: matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]] Output: [1,2,3,4,8,12,11,10,9,5,6,7]

 

Constraints:

• m == matrix.length
• n == matrix[i].length
• 1 <= m, n <= 10
• -100 <= matrix[i][j] <= 100

코드: Python3

class Solution:
    def spiralOrder(self, matrix: List[List[int]]) -> List[int]:
        row = len(matrix)
        col = len(matrix[0])
        ans = []
        
        if row == 0:
            return ans
        
        limit = 0
        for_limit = row * col
        idx_limit = 0
        
        i = 0
        j = 0
        
        while limit < for_limit:
            
            for k in range(j,col):
                limit += 1
                ans.append(matrix[i][k])
            
            if limit == for_limit:
                return ans
            
            j = col-1
            i += 1
            
            
            for k in range(i,row):
                limit += 1
                ans.append(matrix[k][j])
            
            if limit == for_limit:
                return ans
            
            i = row-1
            j -= 1
            
            for k in range(j,idx_limit-1,-1):
                limit += 1
                ans.append(matrix[i][k])
            
            if limit == for_limit:
                return ans
            
            # i = 2
            # j = 1
            
            # tar = matrix[1][0]
            i -= 1 # 1
            j = idx_limit # 0
            idx_limit += 1 # 1
             
            for k in range(i,idx_limit-1,-1):
                limit += 1
                ans.append(matrix[k][j])
                
            i = idx_limit
            j = idx_limit
            col -= 1
            row -= 1
            
        return ans