Compilare: user.cpp: In function ‘void dfs(int, int, int)’: user.cpp:37:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < l[x].size(); ++i) ~~^~~~~~~~~~~~~ user.cpp:30:9: warning: unused variable ‘aux’ [-Wunused-variable] int aux, lvl = 0; ^~~ user.cpp:30:14: warning: unused variable ‘lvl’ [-Wunused-variable] int aux, lvl = 0; ^~~ user.cpp: In function ‘int lca(int, int)’: user.cpp:95:16: warning: unused variable ‘lvl’ [-Wunused-variable] int diffh, lvl = 0; ^~~ user.cpp: In function ‘int solve(int, int, int)’: user.cpp:129:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(indspeeds < speeds.size() && speeds[indspeeds].first <= k) ~~~~~~~~~~^~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:165:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < q.size(); ++i) ~~^~~~~~~~~~ user.cpp:136:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("viteza.in", "r", stdin); ^ user.cpp:137:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("viteza.out", "w", stdout); ^ user.cpp:139:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:142:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^ user.cpp:148:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &x); ^ user.cpp:155:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &k); ^