Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:48:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < gf[node].size(); ++i) { ^ In file included from /usr/include/c++/4.8/cassert:43:0, from /usr/include/i386-linux-gnu/c++/4.8/bits/stdc++.h:33, from user.cpp:1: user.cpp: In function ‘int main()’: user.cpp:71:11: warning: comparisons like ‘X<=Y<=Z’ do not have their mathematical meaning [-Wparentheses] assert(1 <= m <= 150000); ^ user.cpp:93:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < edges.size(); ++i) { ^ user.cpp:96:13: warning: unused variable ‘cul’ [-Wunused-variable] for (auto cul : mySet[x]) { ^ user.cpp:95:7: warning: unused variable ‘y’ [-Wunused-variable] int y = edges[i].second; ^ user.cpp:62:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tribes.in", "r", stdin); ^ user.cpp:63:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("tribes.out", "w", stdout); ^