[ITSA][DP][15th 精] Problem 4. Group without direct leaders
Problem 4. Group without direct leaders(Time Limit: 5 seconds)Problem DescriptionIn X company, everyone, except the CEO, has a direct leader. There are n persons in the company and everyone has a unique ID from 0 to n-1. The ID of the CEO is 0, and the ID of any one is larger tha...