Compilare: user.cpp: In function ‘bool check(const std::vector<std::pair<int, int> >&, const std::vector<std::pair<int, int> >&)’: user.cpp:49:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); ++i) { ^ user.cpp: In function ‘int main()’: user.cpp:93:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < v.size() - 1; ++i) { ^ user.cpp: In function ‘bool check(const std::vector<std::pair<int, int> >&, const std::vector<std::pair<int, int> >&)’: user.cpp:54:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:56:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zaharel.in", "r", stdin); ^ user.cpp:57:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("zaharel.out", "w", stdout); ^ user.cpp:59:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ user.cpp:64:35: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %c\n", &a, &b, &ch); ^