Compilare: user.cpp: In function ‘void solve()’: user.cpp:76:8: warning: unused variable ‘i’ [-Wunused-variable] ll i, j, delta, lini, rini, dif, abs_delta; ^ user.cpp:76:11: warning: unused variable ‘j’ [-Wunused-variable] ll i, j, delta, lini, rini, dif, abs_delta; ^ user.cpp: In function ‘int main()’: user.cpp:114:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("manhattan.in", "r", stdin); ^ user.cpp:115:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("manhattan.out", "w", stdout); ^ user.cpp:117:54: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &Z1.x1, &Z1.y1, &Z1.x2, &Z1.y2); ^ user.cpp:118:54: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d%d", &Z2.x1, &Z2.y1, &Z2.x2, &Z2.y2); ^