#include "leetcode.h" class Solution { public: vvd findWinners(vvd & matches) { map lost; for (auto m : matches) { if (!lost.count(m[0])) lost[m[0]] = 0; lost[m[1]]++; } vector zero, ones; for (auto [k, l] : lost) { if (l == 0) zero.push_back(k); if (l == 1) ones.push_back(k); } return {zero, ones}; } };