leetcode/code/lc54.java at master · mJackie/leetcode · GitHub

History

70 lines (69 loc) · 1.85 KB

Raw

package code;

* 54. Spiral Matrix

* 题意：螺旋输出矩阵

* 难度：Medium

* 分类：Array

* 思路：很直接的思路，就是循环打印

* Tips：需要注意很多细节，最后调试成功

import java.util.ArrayList;

import java.util.List;

public class lc54 {

public static void main(String[] args) {

int[][] matrix = {{1,2,3,4},{5,6,7,8},{9,10,11,12}};

System.out.println(spiralOrder(matrix));

}

public static List<Integer> spiralOrder(int[][] matrix) {

List<Integer> res = new ArrayList<>();

if(matrix.length==0) return res;

int r=0, c=-1; // -1开始，循环内首先++

int row_r = matrix.length;

int col_r = matrix[0].length;

int row_l = -1;

int col_l =-1;

while( row_l+1<row_r || col_l+1<col_r ){

c++;

if(c<col_r){

while(c<col_r){

res.add(matrix[r][c]);

c++;

}

}else //提前终止

return res;

c--; // -- 恢复正常

r++;

if(r<row_r) {

while (r < row_r) {

res.add(matrix[r][c]);

r++;

}

}else

return res;

r--;

c--;

if(c>col_l){

while(c>col_l){

res.add(matrix[r][c]);

c--;

}

}else

return res;

c++;

r--;

if(r>row_l+1) {

while (r > row_l + 1) {

res.add(matrix[r][c]);

r--;

}

}else

return res;

r++;

row_l++;

row_r--;

col_l++;

col_r--;

}

return res;

}

leetcode/code/lc54.java at master · mJackie/leetcode · GitHub

Expand file tree

Breadcrumbs

lc54.java

Latest commit

History

Breadcrumbs

lc54.java

File metadata and controls