输入一个矩阵,按照从外向里以顺时针的顺序依次打印出每一个数字。
示例 1:
输入:matrix = [[1,2,3],[4,5,6],[7,8,9]]
输出:[1,2,3,6,9,8,7,4,5]
示例 2:
输入:matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
输出:[1,2,3,4,8,12,11,10,9,5,6,7]
class Solution { public int[] spiralOrder(int[][] matrix) { if(matrix.length == 0) return new int[0]; int l = 0, r = matrix[0].length - 1, t = 0, b = matrix.length - 1, x = 0; int[] res = new int[(r + 1) * (b + 1)]; while(true) { for(int i = l; i <= r; i++) res[x++] = matrix[t][i]; // left to right. if(++t > b) break; for(int i = t; i <= b; i++) res[x++] = matrix[i][r]; // top to bottom. if(l > --r) break; for(int i = r; i >= l; i--) res[x++] = matrix[b][i]; // right to left. if(t > --b) break; for(int i = b; i >= t; i--) res[x++] = matrix[i][l]; // bottom to top. if(++l > r) break; } return res; } }
此题考查的是边界问题,没有什么算法 搞懂逻辑就ok