Compilare: user.cpp: In function ‘int main()’: user.cpp:56:10: warning: unused variable ‘c’ [-Wunused-variable] char c,*s; ^ user.cpp:55:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&m); ^ user.cpp:62:12: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ user.cpp:65:20: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s); ^ /tmp/ccaHVn3a.o: In function `main': user.cpp:(.text.startup+0x102): warning: the `gets' function is dangerous and should not be used.