Compilare: main.cpp: In function 'int main()': main.cpp:78:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < cbc[i].size(); j++) ~~^~~~~~~~~~~~~~~ main.cpp:59:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.in", "r", stdin); ^ main.cpp:60:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("biconex.out", "w", stdout); ^ main.cpp:63:25: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &m); ^ main.cpp:65:27: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^