Compilare: user.cpp: In function ‘int main()’: user.cpp:30:15: warning: unused variable ‘b’ [-Wunused-variable] int i, x, y, b, ans = 0; ^ user.cpp:28:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("banana.in", "r", stdin); ^ user.cpp:29:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("banana.out", "w", stdout); ^ user.cpp:32:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &N, &K); ^ user.cpp:34:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^