Compilare: main.cpp: In function 'int main()': main.cpp:75:28: warning: format '%d' expects argument of type 'int', but argument 2 has type 'std::vector<int>::size_type {aka long unsigned int}' [-Wformat=] printf("%d\n", sol.size()); ^ main.cpp:41:33: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("graf.in" ,"r", stdin); ^ main.cpp:42:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("graf.out" ,"w", stdout); ^ main.cpp:45:36: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &n, &m, &x, &y); ^ main.cpp:48:26: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &u, &v); ^