Ctrl K

Coding problems

Algorithm problems with tests in Python, JavaScript, Java, Go and C++, checked on our server.

Left, Node, RightStack · Tree · Depth-First SearchEasyCounting Search Tree ShapesTree · Binary Search Tree · MathMediumIs It a Search Tree?Tree · Depth-First Search · Binary Search TreeMediumTwo Mixed-Up NodesTree · Depth-First Search · Binary Search TreeMediumIdentical TreesTree · Depth-First Search · Breadth-First SearchEasyMirror-Image TreeTree · Depth-First Search · Breadth-First SearchEasyTree Rows by DepthTree · Breadth-First Search · Binary TreeMediumSnake Through the Tree LevelsTree · Breadth-First Search · Binary TreeMediumTree HeightTree · Depth-First Search · Breadth-First SearchEasyTree From Pre-Order and In-Order WalksTree · Array · Hash TableMediumTree From In-Order and Post-Order WalksTree · Array · Hash TableMediumTree Levels From the Bottom UpTree · Breadth-First Search · Binary TreeMediumBalanced Tree from a Sorted ListTree · Binary Search Tree · ArrayEasyTree From a Sorted ChainTree · Binary Search Tree · Linked ListMediumEvenly Grown TreeTree · Depth-First Search · Binary TreeEasyNearest Leaf DepthTree · Depth-First Search · Breadth-First SearchEasyLeaf Path With a Given TotalTree · Depth-First Search · Breadth-First SearchEasyAll Leaf Paths With a Given TotalTree · Depth-First Search · BacktrackingMediumTree Into a Right ChainStack · Tree · Depth-First SearchMediumHeaviest Path in a TreeTree · Depth-First Search · Dynamic ProgrammingHardDigit Branch TotalsTree · Depth-First Search · Binary TreeMediumParent Before ChildrenStack · Tree · Depth-First SearchEasyChildren Before ParentStack · Tree · Depth-First SearchEasyFlip a Tree Along Its Left SpineTree · Depth-First Search · Binary TreeMediumThe Tree Seen From the RightTree · Depth-First Search · Breadth-First SearchMediumSize of a Packed TreeBit Manipulation · Tree · Binary SearchEasyMirror the TreeTree · Depth-First Search · Breadth-First SearchEasyK-th Smallest in a Search TreeTree · Depth-First Search · Binary Search TreeMediumSame-Value SubtreesTree · Depth-First Search · Binary TreeMediumPreorder of a Search TreeStack · Tree · Binary Search TreeMediumRoutes from Root to LeavesTree · Depth-First Search · StringEasyNearest Value in a Search TreeTree · Depth-First Search · Binary Search TreeEasyK Keys Nearest to a TargetStack · Tree · Depth-First SearchHardCounting Up Down the TreeTree · Depth-First Search · Binary TreeMediumTree Columns, Top DownTree · Depth-First Search · Breadth-First SearchMediumChecking a Tree Record With Hash MarksStack · Tree · StringMediumBiggest Search SubtreeTree · Depth-First Search · Binary Search TreeMediumA Party Without Direct BossesTree · Depth-First Search · Dynamic ProgrammingMediumPeel the Leaves Round by RoundTree · Depth-First Search · Binary TreeMediumLeft-Hand Leaves TotalTree · Depth-First Search · Breadth-First SearchEasyDownward Chains With a Given TotalTree · Depth-First Search · Binary TreeMediumRemove a Key From a Search TreeTree · Binary Search Tree · Binary TreeMediumMost Frequent Values in a Search TreeTree · Depth-First Search · Binary Search TreeEasyMost Common Subtree TotalTree · Depth-First Search · Hash TableMediumFirst Value on the Lowest RowTree · Depth-First Search · Breadth-First SearchMediumLargest Value on Each Tree LevelTree · Depth-First Search · Breadth-First SearchMediumTree From Bracket NotationStack · Tree · Depth-First SearchMediumAdd Every Bigger KeyTree · Depth-First Search · Binary Search TreeMediumLongest Path in a TreeTree · Depth-First Search · Binary TreeEasyTree Outline, CounterclockwiseTree · Depth-First Search · Binary TreeMedium
1 of 4 · 186 problems