Restore Array from Adjacent Pairs with DFS

Today’s random problem was 1743. Restore the Array From Adjacent Pairs. The question asks us to reconstruct an original array given only the adjacent pairs. We know the array has no duplicates and every adjacent pair is unique. Key Insight: 1. The endpoints (first and last elements) will only have one neighbor. 2. All middle elements will have exactly two neighbors. 3. To restore the array, we just need to find one of those "endpoints" and follow the trail! Problem Is Tricky because of Traversal: 1. Finding the Start: We build an graph and look for a node with a degree of 1. If we started in the middle, we’d have to go in two directions, which makes the logic hard. 2. Avoiding Infinite Loops: Since the graph is undirected, when moving from node A to node B, node B will list A as a neighbor. We must pass a prev reference to ensure we don't bounce back and forth between the same two numbers. My Approach: I used a DFS starting from an endpoint. By keeping track of the prev node, we can traverse the entire path linearly until we hit the other endpoint. Complexity: Time: O(n) Space: O(n) #LeetCode #CodingChallenge #SoftwareEngineering #PythonProgramming #DataStructures #Algorithms #GraphTheory #DFS #ProblemSolving #TechInterviewPrep #Python #Java

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