제출 #1025080

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1025080		huutuan	Friend (IOI14_friend)	C++14	46 / 100	185 ms	2772 KiB

friend

#include "friend.h"

#include <bits/stdc++.h>

using namespace std;

namespace sub1{
   bool adj[30][30];
   bool check(int n,int confidence[],int host[],int protocol[]){
      return n<=20;
   }
   int solve(int n,int confidence[],int host[],int protocol[]){
      for (int i=1; i<n; ++i){
         if (protocol[i]==0){
            adj[i][host[i]]=1;
            adj[host[i]][i]=1;
         }else if (protocol[i]==1){
            for (int j=0; j<i; ++j) if (adj[host[i]][j]){
               adj[i][j]=1;
               adj[j][i]=1;
            }
         }else{
            for (int j=0; j<i; ++j) if (adj[host[i]][j] || j==host[i]){
               adj[i][j]=1;
               adj[j][i]=1;
            }
         }
      }
      int ans=0;
      for (int i=0; i<(1<<n); ++i){
         int cur=0;
         bool check=1;
         for (int j=0; j<n; ++j) if (i>>j&1){
            cur+=confidence[j];
            for (int k=j+1; k<n; ++k) if (i>>k&1){
               check&=!adj[j][k];
            }
         }
         if (check) ans=max(ans, cur);
      }
      return ans;
   }
}

namespace sub2{
   bool check(int n,int confidence[],int host[],int protocol[]){
      return *min_element(protocol+1, protocol+n)==1 && *max_element(protocol+1, protocol+n)==1;
   }
   int solve(int n,int confidence[],int host[],int protocol[]){
      return accumulate(confidence, confidence+n, 0);
   }
}

namespace sub3{
   bool check(int n,int confidence[],int host[],int protocol[]){
      return *min_element(protocol+1, protocol+n)==2 && *max_element(protocol+1, protocol+n)==2;
   }
   struct DSU{
      vector<int> lab, val;
      void init(int n, int confidence[]){
         lab.assign(n, -1);
         vector<int>(confidence, confidence+n).swap(val);
      }
      int find_set(int u){
         return lab[u]<0?u:lab[u]=find_set(lab[u]);
      }
      void union_sets(int u, int v){
         u=find_set(u); v=find_set(v);
         if (u!=v){
            if (lab[u]>lab[v]) swap(u, v);
            lab[u]+=lab[v];
            lab[v]=u;
            val[u]=max(val[u], val[v]);
            val[v]=0;
         }
      }
   } dsu;
   int solve(int n,int confidence[],int host[],int protocol[]){
      dsu.init(n, confidence);
      for (int i=1; i<n; ++i) dsu.union_sets(i, host[i]);
      return accumulate(dsu.val.begin(), dsu.val.end(), 0);
   }
}

namespace sub4{
   bool check(int n,int confidence[],int host[],int protocol[]){
      return *min_element(protocol+1, protocol+n)==0 && *max_element(protocol+1, protocol+n)==0;
   }
   const int N=1e3;
   vector<int> g[N];
   int f[N][2];
   int a[N];
   void dfs(int u){
      f[u][0]=0; f[u][1]=a[u];
      for (int v:g[u]) dfs(v), f[u][0]+=max(f[v][0], f[v][1]), f[u][1]+=f[v][0];
   }
   int solve(int n,int confidence[],int host[],int protocol[]){
      for (int i=1; i<n; ++i) g[host[i]].push_back(i);
      for (int i=0; i<n; ++i) a[i]=confidence[i];
      dfs(0);
      return max(f[0][0], f[0][1]);
   }
}

namespace sub5{
   bool check(int n,int confidence[],int host[],int protocol[]){
      return *min_element(protocol+1, protocol+n)==0 && *max_element(protocol+1, protocol+n)==1 && *max_element(confidence, confidence+n)==1;
   }
   struct FlowEdge{
      int u, v, c, f;
      FlowEdge(int _u=0, int _v=0, int _c=0, int _f=0){
         u=_u, v=_v, c=_c, f=_f;
      }
   };
   const int N=1e3+10;
   vector<int> adj[N];
   int a[N], color[N];
   vector<FlowEdge> e;
   vector<int> g[N];
   int dep[N], ptr[N];
   int source, sink;
   void add_edge(int u, int v, int c){
      g[u].push_back(e.size());
      e.emplace_back(u, v, c);
      g[v].push_back(e.size());
      e.emplace_back(v, u, 0);
   }
   bool bfs(){
      memset(dep, -1, sizeof dep);
      dep[source]=0;
      queue<int> q;
      q.push(source);
      while (q.size()){
         int u=q.front(); q.pop();
         if (u==sink) return 1;
         for (int i:g[u]){
            if (dep[e[i].v]!=-1 || e[i].c==e[i].f) continue;
            dep[e[i].v]=dep[u]+1;
            q.push(e[i].v);
         }
      }
      return 0;
   }
   int dfs(int u, int pushed){
      if (u==sink || !pushed) return pushed;
      for (int &cid=ptr[u]; cid<(int)g[u].size(); ++cid){
         int eid=g[u][cid];
         if (dep[e[eid].v]!=dep[u]+1 || e[eid].c==e[eid].f) continue;
         int t=dfs(e[eid].v, min(pushed, e[eid].c-e[eid].f));
         if (!t) continue;
         e[eid].f+=t;
         e[eid^1].f-=t;
         return t;
      }
      return 0;
   }
   int dinic(){
      int flow=0;
      while (bfs()){
         memset(ptr, 0, sizeof ptr);
         int pushed;
         while ((pushed=dfs(source, 1e9))) flow+=pushed;
      }
      return flow;
   }
   int solve(int n,int confidence[],int host[],int protocol[]){
      int sum=0;
      for (int i=0; i<n; ++i) a[i]=confidence[i], sum+=a[i];
      for (int i=1; i<n; ++i){
         if (protocol[i]==0){
            adj[host[i]].push_back(i);
            adj[i].push_back(host[i]);
            color[i]=color[host[i]]^1;
         }else{
            adj[i]=adj[host[i]];
            color[i]=color[host[i]];
         }
      }
      source=n; sink=n+1;
      for (int i=0; i<n; ++i){
         if (color[i]==0){
            add_edge(source, i, 1);
            for (int j:adj[i]) add_edge(i, j, 1);
         }else{
            add_edge(i, sink, 1);
         }
      }
      return dinic();
   }
}

// Find out best sample
int findSample(int n,int confidence[],int host[],int protocol[]){
   if (sub1::check(n, confidence, host, protocol)) return sub1::solve(n, confidence, host, protocol);
   if (sub2::check(n, confidence, host, protocol)) return sub2::solve(n, confidence, host, protocol);
   if (sub3::check(n, confidence, host, protocol)) return sub3::solve(n, confidence, host, protocol);
   if (sub4::check(n, confidence, host, protocol)) return sub4::solve(n, confidence, host, protocol);
   if (sub5::check(n, confidence, host, protocol)) return sub5::solve(n, confidence, host, protocol);
   return -1;
}

• Subtask 1: 11 / 11
• Subtask 2: 8 / 8
• Subtask 3: 8 / 8
• Subtask 4: 19 / 19
• Subtask 5: 0 / 23
• Subtask 6: 0 / 31