Compilare: main.cpp: In function 'bool pairup(int)': main.cpp:24:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[node].size(); i++) ~~^~~~~~~~~~~~~~~~ main.cpp:34:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[node].size(); i++) ~~^~~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:58:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(j < strlen(s)) ~~^~~~~~~~~~~