Compilare: user.cpp: In function ‘int main()’: user.cpp:143:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<a[n].size(); i++) ^ user.cpp:60:43: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d%d%d%d",&v, &n, &st, &dr); ^ user.cpp:68:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &ct); ^