Compilare: user.cpp: In function ‘bool este_heap(int)’: user.cpp:33:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < o[x].size(); ++i) { ^ user.cpp: In function ‘void dfs(int)’: user.cpp:42:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < o[x].size(); ++i) { ^ user.cpp: In function ‘void preprocess_max_key(int)’: user.cpp:67:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < o[x].size(); ++i) { ^ user.cpp: In function ‘void set_fii(int, int)’: user.cpp:76:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < g[x].size(); ++i) { ^