Compilare: user.cpp:8:6: warning: ISO C++ forbids declaration of ‘main’ with no type [-Wreturn-type] main() { ^ user.cpp: In function ‘int main()’: user.cpp:19:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i<n; i++) { ^ user.cpp:24:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < t.size(); i++) { ^ user.cpp:29:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < t.size(); i++) { ^ user.cpp:31:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < t[i].size(); j++) { ^