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
Notes: This problem needs input-output optimization to run in time. If you are using C++ and you use cin to get your input, add these two lines to the beginning of the main function. You don't need to do anything if you use scanf.