Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:23:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[act].size() ; ++i) ^ user.cpp: In function ‘void makeC(int, int, int&)’: user.cpp:40:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0 ; i < g[act].size() ; ++i) ^ user.cpp: In function ‘int readint()’: user.cpp:103:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer , 1 , bsize , stdin); ^ user.cpp:114:46: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer , 1 , bsize , stdin); ^ user.cpp: In function ‘int main()’: user.cpp:123:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker2.in" , "r" , stdin); ^ user.cpp:124:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker2.out" , "w" , stdout); ^ user.cpp:126:34: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer , 1 , bsize , stdin); ^