Does anyone know how C++ STL map works internally for keys like string? I tried googling, but didn't find much. Does it hash the string for matching or does it match character by character?

30441799 In this code of problem D of last contest (434), he used a map with string as key, it got TLE.

30461043 In this code, he just turned the map into unordered_map, and AC with 2276ms.

Why map and unordered_map differs that much ?