Christmas tree
Practice
0 (0 votes)
Algorithms
Approved
Depth first search
Graphs
Medium
Problem
59% Success 1708 Attempts 50 Points 3s Time Limit 512MB Memory 1024 KB Max Code

Little Santa have to give gifts to N children. There are \(N-1\) roads connecting the homes of N children. Each road has some special Santa tax value which only Santa have to pay. Little Santa is wondering what is the \(realK^{th}\) minimum tax value in the path between the home of child \(realA\) and child \(realB\).

Note: \(k^{th}\) minimum value in a list A is \(k^{th}\) value in the list A after sorting A.

enter image description here

Input format:
First line contains one integer, N \((2 \leq N \leq 7.5 * 10^5)\), denoting the number of children. Next \(N-1\) lines contains three space separated integers each, \(x, y, w\) \((1 \le x, y \le N), (0 \le w \le 10^9)\), denoting that home of child x is connected to home of child y and the tax value of the road is w. Next line will contain an integer, q \((1 \le q \le 7.5*10^5)\), denoting the number of queries. Next q lines contains three space separated integers each, \(a, b\) \((1 \le a, b \le N)\) and k \((1 \le k \le N-1)\).

To generate \(realA\) and \(realB\) you have to use following formulas:

  • \(realA_i = ((a_i - 1 + max(0, lastAns)) \mod n) + 1\)
  • \(realB_i = ((b_i - 1 + 2 * max(0, lastAns)) \mod n) + 1\)
  • \(realK_i = ((k_i - 1 + 3 * max(0, lastAns)) \mod n) + 1\)

Where \(lastAns\) is answer for previous query, or 0 if this is the first query.

Output format:
For each query, print the number the \(realK^{th}\) minimum tax value in the path between the home of child \(realA\) and child \(realB\). Print 1 if there is no such value.

Please login to use the editor

You need to be logged in to access the code editor

Loading...

Please wait while we load the editor

Loading...
Results
Custom Input
Run your code to see the output
Submissions
Please login to view your submissions
Similar Problems
Points:50
Tags:
AlgorithmsGraphsMedium
Points:50
2 votes
Tags:
AlgorithmsDepth First SearchGraphsMedium
Points:50
12 votes
Tags:
AlgorithmsDepth First SearchGraphs