Compilare: main.cpp: In function 'int main()': main.cpp:29:37: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread(buff , 1 , 30000000 , fin); ^ main.cpp:28:30: warning: 'n2' may be used uninitialized in this function [-Wmaybe-uninitialized] int t , n , i , j , n1 , n2 , vall , mch , maxi; ^~ main.cpp:28:25: warning: 'n1' may be used uninitialized in this function [-Wmaybe-uninitialized] int t , n , i , j , n1 , n2 , vall , mch , maxi; ^~