Code
The highlighted line runs next. The pill shows the live values in the running call.
Cost
Work done so far, and how the three solutions compare
The tree
Redrawn after every swap
The highlighted line runs next. The pill shows the live values in the running call.
Work done so far, and how the three solutions compare
Redrawn after every swap
Keyboard: ← → step, Space play or pause. Enter the tree in level order with null for missing children, as LeetCode does (up to 15 nodes, 5 levels, values −100 to 100). Values never change; only left and right pointers are swapped, which is why nodes move when the tree is redrawn.