Problem - D - Codeforces 本番中 "reversal of the bus, take place immediately and this time can be neglected" を「バスの移動は時間がかからない」と勘違いし、とけなかった。。反転だけの時間という事。Let's think about binary searching minimum t…

Problem - E - Codeforces Basic doubling technique, nothing quite special. void solve(){ int N; ll K; cin >> N >> K; vi F( N ), W( N ); for( int i = 0; i < N; ++i ) cin >> F[ i ]; for( int i = 0; i < N; ++i ) cin >> W[ i ]; const int LOGN =…

Problem - D - Codeforces The key is to realize that there are only 3 possible optimal strategies. 1. Drive the car once, and walk for the rest. 2. Keep going with the car no matter what. 3. Drive until the remained distance is not worth to…

Problem - E - Codeforces It was quite disgusting, for many optimisations were required. I read pekempey's article and I think it is easy to understand. pekempey.hatenablog.com The small / large id reference especially made me learn somethi…

Problem - D - Codeforces This is actually a good problem. While as always xor-sum will give us only the xor-sum of the values that appeared odd number of times in the range, we have to find the xor-sum of each number that appeared even num…