Compilare: user.cpp: In function ‘void quicksort(int*, int*)’: user.cpp:14:13: warning: unused variable ‘pivot’ [-Wunused-variable] int pivot = begin[ n >> 1]; ^ user.cpp: In function ‘int main()’: user.cpp:35:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algsort.in", "r", stdin); ^ user.cpp:36:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algsort.out", "w", stdout); ^ user.cpp:38:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &N); ^ user.cpp:41:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &v[i]); ^