54. 螺旋矩阵

LeetCode_54

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题目描述

代码实现

class Solution {
    public List<Integer> spiralOrder(int[][] matrix) {
        int m = matrix.length;//行
        int n = matrix[0].length;//列
        int total = m * n;
        int[][] direction = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};//螺旋矩阵的方向数组
        List<Integer> list = new ArrayList<>();
        int currenti = 0, currentj = 0;
        int currentD = 0;//当前旋转的方向---右下左上
        boolean[][] isTravel = new boolean[m][n];
        for(int i = 0; i< total; i++){
            list.add(matrix[currenti][currentj]);
            isTravel[currenti][currentj] = true;
            int tempi = currenti + direction[currentD][0];
            int tempj = currentj + direction[currentD][1];
            if(tempi < 0 || tempi >= m || tempj < 0 || tempj >=n || isTravel[tempi][tempj]){
                currentD = (currentD + 1) % 4;
            }
            currenti = currenti + direction[currentD][0];
            currentj = currentj + direction[currentD][1];
        }
        return list;
    }
}