Compilare: user.cpp: In function ‘bool check(int, int)’: user.cpp:50:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[node].size(); i++) ^ user.cpp:59:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[node].size(); i++) ^ user.cpp:53:9: warning: unused variable ‘last’ [-Wunused-variable] int last = 0; ^ user.cpp: In function ‘void Solve(int, int)’: user.cpp:102:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[node].size(); i++) ^ user.cpp: In function ‘void DFS(int)’: user.cpp:130:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[node].size(); i++) ^ user.cpp:137:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < G[node].size(); i++) ^ user.cpp: In function ‘void printSolution()’: user.cpp:160:13: warning: unused variable ‘cnt’ [-Wunused-variable] int cnt = 0; ^ user.cpp: In function ‘int main()’: user.cpp:187:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("optic.out", "w", stdout); ^