Compilare: user.cpp: In function ‘void makePaths(int, int, int)’: user.cpp:68:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[node].size(); i++) { ~~^~~~~~~~~~~~~~~~ user.cpp:95:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G[node].size(); i++) { ~~^~~~~~~~~~~~~~~~ user.cpp: In function ‘void reversePathsAndMakeTrees()’: user.cpp:106:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < paths.size(); i++) { ~~^~~~~~~~~~~~~~ user.cpp:112:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < aux.size(); j++) { ~~^~~~~~~~~~~~ user.cpp: In function ‘void query(int)’: user.cpp:136:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &o, &x, &y); ^ user.cpp: In function ‘int main()’: user.cpp:148:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("heavypath.in", "r", stdin); ^ user.cpp:150:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:152:60: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for (int i = 1; i <= n; i++) scanf("%d", &nodes[i].val); ^ user.cpp:155:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^