An org chart tool imports reporting lines from a spreadsheet. People are numbered 0 to n - 1, and each lines[i] = [a, b] is a reporting line between a and b (direction doesn't matter here).
The chart is valid only if the lines form a tree: everyone is connected, and there are no loops. Write isTree(n, lines) that returns true if they do and false otherwise.
Input: n = 4, lines = [[0,1],[0,2],[2,3]] Output: true
Everyone is connected through 3 lines, with no loop.
Input: n = 4, lines = [[0,1],[1,2],[2,0]] Output: false
0, 1, and 2 form a loop, and person 3 isn't connected at all.
1 <= n <= 100000 <= lines.length <= 200000 <= a, b < nRun tries your code on the examples. Submit runs every test, including hidden edge cases, and solves the problem when they all pass.
Ctrl + Enter runs, Ctrl + Shift + Enter submits (⌘ on a Mac).
I'm here to help with #448 Is the Org Chart a Tree?. I give hints, never the solution, so you get to solve it yourself. Ask for a hint, select code to ask about it, or press Ask Tuto why on a failing test.
Your first 3 answers need no account. for free to keep asking.