You are given an integer n
and an undirected, weighted tree rooted at node 1 with n
nodes numbered from 1 to n
. This is represented by a 2D array edges
of length n - 1
, where edges[i] = [ui, vi, wi]
indicates an undirected edge from node ui
to vi
with weight wi
.
You are also given a 2D integer array queries
of length q
, where each queries[i]
is either:
[1, u, v, w']
– Update the weight of the edge between nodes u
and v
to w'
, where (u, v)
is guaranteed to be an edge present in edges
.[2, x]
– Compute the shortest path distance from the root node 1 to node x
.Return an integer array answer
, where answer[i]
is the shortest path distance from node 1 to x
for the ith
query of [2, x]
.
Example 1:
Input: n = 2, edges = [[1,2,7]], queries = [[2,2],[1,1,2,4],[2,2]]
Output: [7,4]
Explanation:
[2,2]
: The shortest path from root node 1 to node 2 is 7.[1,1,2,4]
: The weight of edge (1,2)
changes from 7 to 4.[2,2]
: The shortest path from root node 1 to node 2 is 4.Example 2:
Input: n = 3, edges = [[1,2,2],[1,3,4]], queries = [[2,1],[2,3],[1,1,3,7],[2,2],[2,3]]
Output: [0,4,2,7]
Explanation:
[2,1]
: The shortest path from root node 1 to node 1 is 0.[2,3]
: The shortest path from root node 1 to node 3 is 4.[1,1,3,7]
: The weight of edge (1,3)
changes from 4 to 7.[2,2]
: The shortest path from root node 1 to node 2 is 2.[2,3]
: The shortest path from root node 1 to node 3 is 7.Example 3:
Input: n = 4, edges = [[1,2,2],[2,3,1],[3,4,5]], queries = [[2,4],[2,3],[1,2,3,3],[2,2],[2,3]]
Output: [8,3,2,5]
Explanation:
[2,4]
: The shortest path from root node 1 to node 4 consists of edges (1,2)
, (2,3)
, and (3,4)
with weights 2 + 1 + 5 = 8
.[2,3]
: The shortest path from root node 1 to node 3 consists of edges (1,2)
and (2,3)
with weights 2 + 1 = 3
.[1,2,3,3]
: The weight of edge (2,3)
changes from 1 to 3.[2,2]
: The shortest path from root node 1 to node 2 is 2.[2,3]
: The shortest path from root node 1 to node 3 consists of edges (1,2)
and (2,3)
with updated weights 2 + 3 = 5
.
Constraints:
1 <= n <= 105
edges.length == n - 1
edges[i] == [ui, vi, wi]
1 <= ui, vi <= n
1 <= wi <= 104
edges
represents a valid tree.1 <= queries.length == q <= 105
queries[i].length == 2
or 4
queries[i] == [1, u, v, w']
or,queries[i] == [2, x]
1 <= u, v, x <= n
(u, v)
is always an edge from edges
.1 <= w' <= 104