Compilare: user.cpp: In function ‘int main()’: user.cpp:23:13: warning: unused variable ‘p’ [-Wunused-variable] int i,x,p; ^ user.cpp:21:40: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in,"%d %d %d\n", &n, &a, &b); ^ user.cpp:22:23: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,100010,in); ^