Compilare: user.cpp: In function ‘void makeaint(int)’: user.cpp:83:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < chain[nr].size(); i++) { ^ user.cpp:91:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 1; i <= 4 * chain[nr].size(); i++) ^ user.cpp: In function ‘void build()’: user.cpp:102:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < chain[i].size(); j++) ^ user.cpp: In function ‘void dfs(int, int)’: user.cpp:59:18: warning: ‘chn’ may be used uninitialized in this function [-Wmaybe-uninitialized] cno[node] = chn; ^