Compilare: main.cpp: In function 'bool check_ab(int)': main.cpp:59:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < rel_dist.size() - 1; i++) ~~^~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:84:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("harta3.in", "r", stdin); ^ main.cpp:85:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("harta3.out", "w", stdout); ^ main.cpp:87:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d %d", &n, &m, &a, &b); ^ main.cpp:90:34: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d", &x, &y, &d); ^