POJ-2926-Requirements&&Educational Codeforces Round 56G. Multidimensional Queries 【哈夫曼距离】

POJ2926

先学会这个哈夫曼距离的处理才能做 cf 的G

#include <iostream>
#include <stdio.h>
#include <algorithm>
#include <cstring>
#include <cmath>
using namespace std;
#define maxn 100005
const int inf = (int)1e9;
double a[maxn][6];
double mi[1<<5+1],mx[1<<5+1];
int main(){
   int n;
   scanf("%d",&n);
   for(int j=0;j<n;j++){
      for(int k=0;k<5;k++){
         scanf("%lf",&a[j][k]);
      }
   }
   for(int j=0;j<(1<<5);j++){
      mi[j] = inf;
      mx[j] = -inf;
   }
  // double mx = 0,mi = inf;
   double ans = -inf;
   for(int j=0;j<n;j++){
      //int cur = 0.
      for(int k=0;k<(1<<5);k++){
         double cur = 0;
         for(int i=0;i<5;i++){
            if(k&(1<<i)){
               cur += a[j][i];
            }else{
               cur -= a[j][i];
            }
         }
         //cout<<cur<<endl;
         mx[k] = max(mx[k],cur);
         mi[k] = min(mi[k],cur);
         //ans = max(ans,mx[j]-mi[j]);
      }
   }
   for(int j=0;j<(1<<5);j++){
      //cout<<mx[j]<<" "<<mi[j]<<endl;
      ans = max(ans,mx[j]-mi[j]);
   }
   printf("%0.2f\n",ans);

}

点一下    题目链接

CF G 用线段树处理一下

就ok

#include<bits/stdc++.h>
using namespace std;
#define maxn 200005
#define inf (int)1e9
int a[4*maxn][33];
int b[4*maxn][6];
int n,m;
void build(int l,int r,int in){
  if(l==r){
     for(int j=0;j<(1<<m);j++){
        int cur = 0;
        for(int k=0;k<m;k++){
           if(j&(1<<k)){
              cur+=b[l][k];
           }else cur-=b[l][k];
        }
        //cout<<cur<<endl;
        a[in][j] = cur;
     }
     return ;
  }
  int mid = (l+r)/2;
  build(l,mid,in*2);
  build(mid+1,r,in*2+1);
  for(int j=0;j<(1<<m);j++){
     a[in][j]=min(a[in*2][j],a[in*2+1][j]);
  }
}
void up(int l,int r,int x,int in){
    if(l==r){
        for(int j=0;j<(1<<m);j++){
          int cur = 0;
          for(int k=0;k<m;k++){
             if(j&(1<<k)){
                cur+=b[l][k];
             }else cur-=b[l][k];
          }
          a[in][j] = cur;
        }
        return ;
    }
    int mid = (l+r)/2;
    if(x>mid){
       up(mid+1,r,x,in*2+1);
    }else{
       up(l,mid,x,in*2);
    }
    for(int j=0;j<(1<<m);j++){
      a[in][j]=min(a[in*2][j],a[in*2+1][j]);
    }
}
int query(int l,int r,int x,int y,int i,int in){
    //if(x>y) return inf;
    if(l==x&&r==y){
       return a[in][i];
    }
     int mid = (l+r)/2;
     if(x>mid){
        return query(mid+1,r,x,y,i,in*2+1);
     }else if(y<=mid){
        return query(l,mid,x,y,i,in*2);
     }
     return min(query(l,mid,x,mid,i,in*2),query(mid+1,r,mid+1,y,i,in*2+1));
}
int main(){
   cin>>n>>m;
   for(int j=1;j<=n;j++){
      for(int k=0;k<m;k++){
         scanf("%d",&b[j][k]);
      }
   }
   build(1,n,1);
//   for(int j=0;j<(1<<m);j++){
//     cout<<a[1][j]<<endl;
//   }
   int t; cin>>t;
   while(t--){
      int z;
      scanf("%d",&z);
      if(z==1){
         int i;
         scanf("%d",&i);
         for(int j=0;j<m;j++){
            scanf("%d",&b[i][j]);
         }
         up(1,n,i,1);
      }else{
         int l,r,mx = 0;
         scanf("%d%d",&l,&r);
         for(int j=0;j<(1<<(m-1));j++){
             int x = query(1,n,l,r,j,1);
             int y = query(1,n,l,r,j^((1<<m)-1),1);
             //cout<<x<<" "<<y<<endl;
             mx = max(mx,abs(x+y));
         }
         printf("%d\n",mx);
      }
   }
   return 0;
}