Compilare: user.cpp: In function ‘int main()’: user.cpp:44:38: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k = 0; k < v[i].size(); k++) ^ user.cpp:54:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i = 0; i < v[0].size(); i++) ^ user.cpp:25:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &nm); ^ user.cpp:28:36: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &a, &b, &c); ^