Compilare: user.cpp: In function ‘int main()’: user.cpp:47:9: warning: unused variable ‘i’ [-Wunused-variable] int i,j; ^ user.cpp:47:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp:48:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d",&n); ^ In file included from /usr/include/string.h:642:0, from /usr/include/c++/4.8/cstring:42, from user.cpp:4: In function ‘void* memset(void*, int, size_t)’, inlined from ‘void fib(int)’ at user.cpp:39:30: /usr/include/i386-linux-gnu/bits/string3.h:82:32: warning: call to ‘__warn_memset_zero_len’ declared with attribute warning: memset used with constant zero length parameter; this could be due to transposed parameters [enabled by default] __warn_memset_zero_len (); ^ /tmp/ccwosjYy.o: In function `fib(int)': user.cpp:(.text+0x374): warning: memset used with constant zero length parameter; this could be due to transposed parameters