Compilare: user.cpp: In function ‘int main()’: user.cpp:139:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=lg; i>=2 && strlen(nr1)<l; i--) ^ user.cpp:159:49: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] if(lg>0)ch=nr1[lg-1];else ch=NULL; ^ user.cpp:165:49: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] if(lg>0)ch=nr2[lg-1];else ch=NULL; ^ user.cpp:170:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(strlen(nr1)<l) ^ user.cpp:185:44: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(v[1].c>=4 && strlen(nr1)<l) ^ user.cpp:202:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(strlen(nr1)<l) ^ user.cpp:218:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(strlen(nr1)+strlen(nr2)<n) ^ user.cpp:15:13: warning: unused variable ‘upoz’ [-Wunused-variable] int i,j,upoz=0,l,n=0,val,lg = 0; ^ user.cpp:6:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pal.in","r",stdin); ^ user.cpp:7:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("pal.out","w",stdout); ^ user.cpp:18:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&l,&val); ^ user.cpp:27:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&val); ^