Compilare: user.cpp: In function ‘void createPath(int, char*)’: user.cpp:28:13: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] pt[ln+1]=NULL; ^ user.cpp:34:17: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] pt[ln+1]=NULL; ^ user.cpp: In function ‘void efolder(int)’: user.cpp:76:28: warning: NULL used in arithmetic [-Wpointer-arith] while(s[i]!=')'&&s[i]!=NULL) ^ user.cpp:83:17: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] t[j]=NULL; ^ user.cpp:91:17: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] t[j]=NULL; ^ user.cpp:75:10: warning: variable ‘t’ set but not used [-Wunused-but-set-variable] char t[256]; ^ user.cpp: In function ‘int main()’: user.cpp:119:9: warning: unused variable ‘n’ [-Wunused-variable] int n=strlen(s)-1; ^ user.cpp: In function ‘int dir(int)’: user.cpp:48:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘bool name(int)’: user.cpp:55:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:116:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dir.in","r",stdin); ^ user.cpp:117:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dir.out","w",stdout); ^