Compilare: user.cpp: In function ‘int main()’: user.cpp:23:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] { freopen("sstabil.in","r",stdin); ^ user.cpp:24:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sstabil.out","w",stdout); ^ user.cpp:27:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d\n",&n); ^ user.cpp:28:30: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(v+1,10000000,stdin); ^ user.cpp:16:27: warning: ‘pos’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(i==pos) x[i]=ma+'0',s++; ^ user.cpp:5:20: note: ‘pos’ was declared here { int sum,i,ma=0,pos; ^ user.cpp:16:27: warning: ‘pos’ may be used uninitialized in this function [-Wmaybe-uninitialized] if(i==pos) x[i]=ma+'0',s++; ^ user.cpp:5:20: note: ‘pos’ was declared here { int sum,i,ma=0,pos; ^ In file included from /usr/include/stdio.h:934:0, from /usr/include/c++/4.8/cstdio:42, from user.cpp:1: In function ‘char* fgets(char*, int, FILE*)’, inlined from ‘int main()’ at user.cpp:28:30: /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); ^