Compilare: main.cpp: In function 'void dfs_makedp(int, int, int)': main.cpp:109:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < grn[nod].size();i++){ ~~^~~~~~~~~~~~~~~~~ main.cpp:113:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < grm[nodb].size();j++){ ~~^~~~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:162:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sakura.in", "r", stdin); ^ main.cpp:163:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("sakura.out", "w", stdout); ^