【离散化】离散化入门

离散化应用

离散化模板

  vector<int> alls;
  sort(alls.begin(), alls.end());
  alls.erase(unique(alls.begin(),alls.end()), alls.end());

  //获取离散化后的映射
  int find(int x)
  {
    int mid, l = 0, r = alls.size()-1;
    while(l < r)
    {
        mid = l + r >> 1;
        if(alls[mid] >= x) r = mid;
        else l = mid + 1;
    }
    return r+1; //从1开始映射，不+1则为0
  }