标签：color ret div int sort shm solution assets const
Given a m * n matrix mat of integers, sort it diagonally in ascending order from the top-left to the bottom-right then return the sorted array.
Example 1:
Input: mat = [[3,3,1,1],[2,2,1,2],[1,1,1,2]] Output: [[1,1,1,1],[1,2,2,2],[1,2,3,3]]
Constraints:
m == mat.lengthn == mat[i].length1 <= m, n <= 1001 <= mat[i][j] <= 100class Solution { public int[][] diagonalSort(int[][] mat) { int m = mat.length, n = mat[0].length; Map<Integer, PriorityQueue<Integer>> map = new HashMap(); for(int i = 0; i < m; i++){ for(int j = 0; j < n; j++){ map.putIfAbsent(i-j, new PriorityQueue()); map.get(i - j).offer(mat[i][j]); } } for(int i = 0; i < m; i++){ for(int j = 0; j < n; j++){ mat[i][j] = map.get(i - j).poll(); } } return mat; } }
putIfAbsent，如果key不存在就put，存在就不用管
对角线有什么特性？
下表相减相同 -- i - j。
什么东西能自动排序？
PriorityQueue
1329. Sort the Matrix Diagonally
标签：color ret div int sort shm solution assets const
原文地址：https://www.cnblogs.com/wentiliangkaihua/p/12239553.html
