Compilare: main.cpp: In function 'void dfs1(int)': main.cpp:34:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < a[x].size(); i++) ~~^~~~~~~~~~~~~ main.cpp: In function 'void read()': main.cpp:62:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (j = 0; j < s.size(); j++) { ~~^~~~~~~~~~