Compilare: user.cpp: In function ‘int main()’: user.cpp:56:21: warning: unused variable ‘a’ [-Wunused-variable] int n, i, x, y, a, b; ^ user.cpp:56:24: warning: unused variable ‘b’ [-Wunused-variable] int n, i, x, y, a, b; ^ user.cpp:58:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &n,&m); ^ user.cpp:60:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x, &y); ^