Add stack-queue module: ten stack and queue interview problems, monotonic stack, min stack, queue from stacks and stack from a queue, brute-force cross-checks, dry-run traces, operation counts, pitfalls (11 tests)

Co-Authored-By: Claude Sonnet 5.5 <[email protected]> Claude-Session: https://claude.ai/code/session_017ic4b6nxynun5JFivebVb1
2026-11-12 22:35:43 +05:30
parent c5c435ae20
commit b9aeb78b24
36 changed files with 2164 additions and 0 deletions
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+Reverse Polish Notation: stack after every token
+================================================
+
+tokens: [2, 1, +, 3, *]   result = 9
+  token 2: push 2   stack(top first) = [2]
+  token 1: push 1   stack(top first) = [1, 2]
+  token +: pop 1 then 2, compute 2 + 1 = 3   stack(top first) = [3]
+  token 3: push 3   stack(top first) = [3, 3]
+  token *: pop 3 then 3, compute 3 * 3 = 9   stack(top first) = [9]
+
+tokens: [4, 13, 5, /, +]   result = 6
+  token 4: push 4   stack(top first) = [4]
+  token 13: push 13   stack(top first) = [13, 4]
+  token 5: push 5   stack(top first) = [5, 13, 4]
+  token /: pop 5 then 13, compute 13 / 5 = 2   stack(top first) = [2, 4]
+  token +: pop 2 then 4, compute 4 + 2 = 6   stack(top first) = [6]
+