zoj 3437 Very Hard Problem

#include <iostream>  #include <cstdio>  #include <memory.h>  #include <cstdlib>  #include <limits.h>  #include <cstring>  using namespace std;  const int maxn = 100;  int main(){      char str[maxn];      long long base, sign;      char opt, trash;      while(cin >> opt >> base >> str){          long long ans = strtoll(str, NULL, base);          if(opt == '-'){   if(ans == LLONG_MIN)printf("%llun", (unsigned long long)ans);   else printf("%lldn", -ans);   continue;          }else if(opt == '~'){   ans = ~ans;}else{   ans = !ans;          }          printf("%lldn", ans);      }      return 0;  }