Compilare: user.cpp: In function ‘int main()’: user.cpp:16:22: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while(!(x[i]>='a'&&x[i]<='z'||x[i]>='A'&&x[i]<='Z')) ^ user.cpp:19:20: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while(x[i]>='a'&&x[i]<='z'||x[i]>='A'&&x[i]<='Z') ^ user.cpp:10:18: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(x,1000,f); ^ In file included from /usr/include/stdio.h:934:0, from user.cpp:1: In function ‘char* fgets(char*, int, FILE*)’, inlined from ‘int main()’ at user.cpp:10:18: /usr/include/i386-linux-gnu/bits/stdio2.h:253:58: warning: call to ‘__fgets_chk_warn’ declared with attribute warning: fgets called with bigger size than length of destination buffer [enabled by default] return __fgets_chk_warn (__s, __bos (__s), __n, __stream); ^