Now I get it, I was misinterpreting question all this time. Actually after finish of each round, lead is not the difference between points of that round. But the lead is difference between the points achieved through all rounds including current round - Lakpa Tashi Bhutia
Yesterday night I went to the nearby cyber cafe to attend the first programming contest of my life. But I had to complete the contest in 1/3 time as the cyber cafe was about to get closed by 9:00 p.m.(Don't have PC at home, this I am writing from my school lab.).
Made a new codechef account for the same purpose, settled myself on a computer with 20 mins to go for the contest.
The wait ended and and the problems flashed on the screen.
Started the first problem with full excitement. The problem was set by Udit Sanghi, and the problem statement started with something bad about schools(What else did you expected) which on one go I understood it is unsolvable for me, atleast in the given time constraints. Went for the another problem "Ant in a Box", Ahhh this was the problem I came for, but the genius inside me thought that following formulas are same