Compilare: user.cpp: In function ‘void top(int)’: user.cpp:15:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < vt[act].size(); i ++) { ^ user.cpp: In function ‘int main()’: user.cpp:31:13: warning: unused variable ‘k’ [-Wunused-variable] int k, x; f >> d[i]; ^ user.cpp:41:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < v[i].size(); j ++) { ^ user.cpp:47:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0; k < ans.size(); k ++) { ^ user.cpp:50:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0; j < vt[i].size(); j ++) { ^