Compilare: main.cpp: In function 'int main()': main.cpp:57:28: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<std::vector<int> >::size_type {aka long unsigned int}' [-Wformat=] printf("%d\n", sol.size()); ^ main.cpp:46:36: 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:47:38: 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:49:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ main.cpp:52:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &u, &v); ^