Compilare: user.cpp: In function ‘void quicksort(int, int)’: user.cpp:6:23: warning: unused variable ‘t’ [-Wunused-variable] int pivot,j,i,aux,t; ^ user.cpp: In function ‘int main()’: user.cpp:42:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("excel.in","r",stdin); ^ user.cpp:43:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("excel.out","w",stdout); ^ user.cpp:67:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&a[3][n]); ^