Compilare: user.cpp: In function ‘int main()’: user.cpp:63:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i < v[x].size(); ++i) { ^ user.cpp:39:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n, &m); ^ user.cpp:42:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d", &x, &y, &c); ^