Pattern4 visualizers
Iterative Stack Pattern Visualizers
The Iterative Stack pattern is a recurring algorithmic shape that appears across coding interviews and competitive problems. Use it when the problem geometry matches its trigger conditions — recognizing the pattern collapses what looks like a hard problem into a familiar template. These visualizers trace Iterative Stack step-by-step on classics such as Binary Tree Inorder Traversal - Iterative, Binary Tree Postorder Traversal - One Stack, Binary Tree Postorder Traversal - Two Stacks, so you can internalize the moves before you ever need them under pressure.
Binary Tree
Binary Tree Inorder Traversal - Iterative
Iterative inorder using curr pointer + stack. Two-phase loop: go left (push), then pop-record-go right.
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Binary Tree
Binary Tree Postorder Traversal - One Stack
Iterative postorder with a single stack. Uses curr and lastVisited pointers to avoid revisiting the right subtree.
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Binary Tree
Binary Tree Postorder Traversal - Two Stacks
Iterative postorder using two stacks. Phase 1: fill stack2 in reverse-postorder via stack1. Phase 2: pop stack2 for correct order.
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Binary Tree
Binary Tree Preorder Traversal - Iterative
Iterative DFS using an explicit stack. Push root, then loop: pop → record → push right → push left.
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