Compilare: main.cpp: In function 'int main()': main.cpp:66:29: 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:67:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < sol.size() ; i++) ~~^~~~~~~~~~~~ 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:43:34: 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:46:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&u,&v); ^