Compilare: user.cpp: In function ‘void solve(int)’: user.cpp:25:10: warning: unused variable ‘j’ [-Wunused-variable] int i, j; ^ user.cpp: In function ‘int main()’: user.cpp:54:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &n); ^ user.cpp:56:46: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d%d", &a[i], &b[i], &c[i]); ^