{"id":"findtilt-single-pass-postorder","text":"`findTilt` computes total tilt in a single O(n) postorder traversal by having `subtree_sum` return the value sum upward while accumulating tilt into a `nonlocal` closure variable as a side effect.","truth_value":"IN","source":"entries/2026/06/06/binary-tree-tilt-solution.md","source_url":"","source_hash":"","justifications":[],"dependents":[],"metadata":{},"created_at":"","updated_at":"","reviewed_at":"","verified_at":"","retracted_at":"","explanation":{"steps":[{"node":"findtilt-single-pass-postorder","truth_value":"IN","reason":"premise"}]}}