It took me a while to fully understand the question, yet there still some grey area which i have missed. I latey understood that since they are giving you cumulative scores, we need to subtract the previous total from it to calculate who is leading in a current round. And i have changed my logic little bit, but something missing. Please help me find it or explain the problem in simple terms with a test case.
My solution:
https://www.codechef.com/viewsolution/44879419