Compilare: user.cpp: In function ‘int main()’: user.cpp:34:15: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] vec[j]=NULL; ^ user.cpp:19:7: warning: unused variable ‘m’ [-Wunused-variable] int n,m,i,j,k=0,x=0,l,c; ^ user.cpp:17:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] {freopen ("reteta2.in","r",stdin); ^ user.cpp:18:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen ("reteta2.out","w",stdout); ^ user.cpp:20:8: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(r); ^ /tmp/ccXaJ25g.o: In function `main': user.cpp:(.text.startup+0x56): warning: the `gets' function is dangerous and should not be used.