Compilare: user.cpp: In function ‘int main()’: user.cpp:21:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<=strlen(s);i++) ^ user.cpp:16:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d%d",&n,&a,&b); ^ user.cpp:18:22: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,600001,f); ^