Compilare: user.cpp: In function ‘void solve(int)’: user.cpp:24:46: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G1[aux + 1].size(); ++i) { ^ user.cpp:31:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < G2[aux].size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:43:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pcb.in", "r", stdin); ^ user.cpp:44:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pcb.out", "w", stdout); ^ user.cpp:47:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &n, &m, &x); ^ user.cpp:50:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^