https://codeforces.net/contest/808/problem/D
unordered_map took me to tle but map took me to ac.
unordered_map submission https://codeforces.net/contest/808/submission/48371065
map submission https://codeforces.net/contest/808/submission/48371396
but we know generally unordered_map works in O(1) time where map works in O(log n) time. so, why this occurs. please.
https://codeforces.net/blog/entry/62393
Generally, if one already know the hash function(like the one in unordered_map) you use in your code, then one could make mean data to blow it up(if your hash function is not safe enough), while map(RBTree) is stable.