엔지니어 게시판
LeetCode 솔루션 분류

[1/12] 1519. Number of Nodes in the Sub-Tree With the Same Label

컨텐츠 정보

본문

1519. Number of Nodes in the Sub-Tree With the Same Label 

You are given a tree (i.e. a connected, undirected graph that has no cycles) consisting of n nodes numbered from 0 to n - 1 and exactly n - 1 edges. The root of the tree is the node 0, and each node of the tree has a label which is a lower-case character given in the string labels (i.e. The node with the number i has the label labels[i]).

The edges array is given on the form edges[i] = [ai, bi], which means there is an edge between nodes ai and bi in the tree.

Return an array of size n where ans[i] is the number of nodes in the subtree of the ith node which have the same label as node i.

A subtree of a tree T is the tree consisting of a node in T and all of its descendant nodes.

 

Example 1:

Input: n = 7, edges = [[0,1],[0,2],[1,4],[1,5],[2,3],[2,6]], labels = "abaedcd"
Output: [2,1,1,1,1,1,1]
Explanation: Node 0 has label 'a' and its sub-tree has node 2 with label 'a' as well, thus the answer is 2. Notice that any node is part of its sub-tree.
Node 1 has a label 'b'. The sub-tree of node 1 contains nodes 1,4 and 5, as nodes 4 and 5 have different labels than node 1, the answer is just 1 (the node itself).

Example 2:

Input: n = 4, edges = [[0,1],[1,2],[0,3]], labels = "bbbb"
Output: [4,2,1,1]
Explanation: The sub-tree of node 2 contains only node 2, so the answer is 1.
The sub-tree of node 3 contains only node 3, so the answer is 1.
The sub-tree of node 1 contains nodes 1 and 2, both have label 'b', thus the answer is 2.
The sub-tree of node 0 contains nodes 0, 1, 2 and 3, all with label 'b', thus the answer is 4.

Example 3:

Input: n = 5, edges = [[0,1],[0,2],[1,3],[0,4]], labels = "aabab"
Output: [3,2,1,1,1]

 

Constraints:

  • 1 <= n <= 105
  • edges.length == n - 1
  • edges[i].length == 2
  • 0 <= ai, bi < n
  • ai != bi
  • labels.length == n
  • labels is consisting of only of lowercase English letters.
Accepted
75.3K
Submissions
135.6K
Acceptance Rate
<div class="text-label-1 dark:text-dark-label-1 text-sm font-medium" style="border-width: 0px; border-style: solid; border-color: var(--chakra-colors-chakra-border-color); border-image: initial; box-sizing: border-box; --tw-border-spacing-x:0; --tw-border-spacing-y:0; --tw-translate-x:0; --tw-translate-y:0; --tw-rotate:0; --tw-skew-x:0; --tw-skew-y:0; --tw-scale-x:1; --tw-scale-y:1; --tw-pan-x: ; --tw-pan-y: ; --tw-pinch-zoom: ; --tw-scroll-snap-strictness:proximity; --tw-ordinal:

관련자료

댓글 1

학부유학생님의 댓글

  • 익명
  • 작성일
from collections import Counter, defaultdict
class Solution:
    def countSubTrees(self, n: int, edges: List[List[int]], labels: str) -> List[int]:
        graph = defaultdict(list)
        for e1, e2 in edges:
            graph[e1].append(e2)
            graph[e2].append(e1)

        res = [0]*n
        
        def dfs(prev, curr):
            
            counter = Counter()
            for nxt in graph[curr]:
                if nxt == prev: continue
                counter = counter + dfs(curr, nxt)
            counter[labels[curr]] += 1
            res[curr] = counter[labels[curr]]

            return counter
        
        dfs(-1, 0)
        return res
전체 349 / 1 페이지
번호
제목
이름

최근글


인기글


새댓글


Stats


알림 0