Redundant Connection

In this problem, a tree is an undirected graph that is connected and has no cycles.

You are given a graph that started as a tree with n nodes labeled from 1 to n, with one additional edge added. The added edge connects two different vertices and creates exactly one cycle.

Return the edge that can be removed so that the resulting graph is a tree of n nodes. If there are multiple answers, return the edge that occurs last in the input.

Function signature

func FindRedundantConnection(edges [][]int) []int

Examples

Example 1:

Input: edges = [[1,2],[1,3],[2,3]]
Output: [2,3]
Explanation:
    1---2
     \ /
      3
Edge [2,3] creates a cycle. Removing it leaves a valid tree.

Example 2:

Input: edges = [[1,2],[2,3],[3,4],[1,4],[1,5]]
Output: [1,4]
Explanation:
      5
      |
      1---2
      |   |
      4---3
Edge [1,4] creates a cycle. It appears last among cycle edges.

Constraints

• n == edges.length
• 3 <= n <= 1000
• edges[i].length == 2
• 1 <= ai < bi <= n
• ai != bi
• There are no repeated edges
• The given graph is connected

Hints

1. Process edges one by one. The edge that would connect two already-connected nodes creates a cycle.
2. Use Union-Find: if union returns false (already connected), that's the redundant edge.
3. Return the last such edge found.

Notes

• The graph is 1-indexed, not 0-indexed.
• There's always exactly one redundant edge.
• If multiple edges could be removed, return the one appearing last in the input.