If we igone the -1 and created a directed graph with 1 as a root. We just need to check is there any cycle ion the graph or not. If we found cycle then the answer is "Not Valid" otherwise "Valid"
Statistics
82%
Solution Ratio
alamkhanEarliest,
nusuBotFastest, 0.1s
insane_curiousLightest, 6.0 MB
Deshi_TouristShortest, 1042B
