Submission #1033737

#	Time	Username	Problem	Language	Result	Execution time	Memory
1033737		vjudge1	Simurgh (IOI17_simurgh)	C++17	51 / 100	711 ms	8704 KiB

simurgh

#include "simurgh.h"
#include<bits/stdc++.h>
using namespace std;
vector<int>R;
int query(){
    return count_common_roads(R);
}
vector<int>U,V;
set<int>subtree[501];
vector<int>AADJ[10010],adj[501];
int indexofr[501][501];
bitset<501>vis;
vector<int>origintree;
int N_,K_;
struct dsu{
    int par[501];
    int abp(int n){
        return par[n]?par[n]=abp(par[n]):n;
    }
    bool merge(int a,int b){
        a=abp(a+1),b=abp(b+1);
        if(a==b) return 0;
        return par[a]=b;
    }
    void reset(){
        memset(par,0,sizeof par);
    }
} tis, TIS2;
void gendfstree(int n){
    vis[n]=1;
    subtree[n].insert(n);
    for(auto i:AADJ[n]){
        if(vis[i])continue;
        gendfstree(i);
        for(auto j:subtree[i])
            subtree[n].insert(j);
        adj[i].push_back(n);
        adj[n].push_back(i);
        origintree.push_back(indexofr[n][i]);
    }
}
void mergethese(set<int>st){
    tis.reset();
    for(int i=0;i<U.size();i++){
        int a=U[i],b=V[i];
        if(!st.count(a)||!st.count(b))
            continue;
        if(tis.merge(a,b))
            R.push_back(i);
    }
    tis.reset();
    for(int i=0;i<U.size();i++){
        int a=U[i],b=V[i];
        if(st.count(a)||st.count(b))
            continue;
        if(tis.merge(a,b))
            R.push_back(i);
    }
}
void specialcheck(int n){

}
vector<int>ans;
void findstuff(int n,int p){
    for(auto i:adj[n])
        if(i-p)findstuff(i,n);
    if(!n)return;
    vector<int>R2=R;
    R.clear();
    mergethese(subtree[n]);
    vector<int>specrod;
    for(auto i:AADJ[n])
        if(subtree[i].size()>subtree[n].size())
            specrod.push_back(indexofr[i][n]);
    map<int,vector<int>>mp;
    for(auto i:specrod){
        R.push_back(i);
        mp[query()].push_back(i);
        R.pop_back();
    }
    vector<int>C=prev(mp.end())->second;
    int D=prev(mp.end())->first;
    if(mp.size()==2){
        for(auto i:C)
            TIS2.merge(U[i],V[i]),
            ans.push_back(i);
    } else {
        int cond=1;
        if(subtree[n].size()==1)
            cond=1;
        else {
            for(int i=0;i<U.size();i++){
                int a=U[i],b=V[i];
                if(a-n&&b-n&&subtree[n].count(a)!=subtree[n].count(b)){
                    R.push_back(i);
                    if(query()+!(count(ans.begin(),ans.end(),i))>D)
                        cond=0;
                    break;
                }
            }
        }
        if(cond) for(auto i:C)
            TIS2.merge(U[i],V[i]),
            ans.push_back(i);
    }
}
std::vector<int> find_roads(int n, std::vector<int> u, std::vector<int> v) {
    U=u;
    V=v;
    N_=n;
    int m=u.size();
    if(m==n-1){
        ans.resize(m);
        iota(ans.begin(),ans.end(),0);
        return ans;
    }
    for(int i=0;i<m;i++)
        AADJ[u[i]].push_back(v[i]),
        AADJ[v[i]].push_back(u[i]),
        indexofr[u[i]][v[i]]=indexofr[v[i]][u[i]]=i;
    gendfstree(0);
    findstuff(0,0);
    return ans;
}

Compilation message (stderr)

simurgh.cpp: In member function 'bool dsu::merge(int, int)':
simurgh.cpp:23:22: warning: suggest parentheses around assignment used as truth value [-Wparentheses]
   23 |         return par[a]=b;
      |                ~~~~~~^~
simurgh.cpp: In function 'void mergethese(std::set<int>)':
simurgh.cpp:44:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |     for(int i=0;i<U.size();i++){
      |                 ~^~~~~~~~~
simurgh.cpp:52:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   52 |     for(int i=0;i<U.size();i++){
      |                 ~^~~~~~~~~
simurgh.cpp: In function 'void findstuff(int, int)':
simurgh.cpp:92:26: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |             for(int i=0;i<U.size();i++){
      |                         ~^~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 17 / 17
• Subtask 3: 21 / 21
• Subtask 4: 0 / 19
• Subtask 5: 0 / 30