Compilare: user.cpp: In function ‘int main()’: user.cpp:80:18: warning: converting to non-pointer type ‘char’ from NULL [-Wconversion-null] a[i][n+1]=NULL; ^ user.cpp:46:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,nr,an1; ^ user.cpp:44:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("compresie.in","r",stdin); ^ user.cpp:45:40: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("compresie.out","w",stdout); ^ user.cpp:48:15: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(si+1); ^ /tmp/cc4IMM8N.o: In function `main': user.cpp:(.text.startup+0x60): warning: the `gets' function is dangerous and should not be used.