関連ワード:  c++ vector unordered_map    c++ unordered_map vs vector    c++ vector as unordered_map key    c++ unordered_map with vector as value    c++ insert vector into unordered_map    c++ convert vector to unordered_map    c++ create vector from unordered_map    c++ unordered_map vs vector performance    c++ unordered_map vs vector of pairs    c++ unordered_map insert vector