Submission #944208

#	Time	Username	Problem	Language	Result	Execution time	Memory
944208		Wansur	Simurgh (IOI17_simurgh)	C++14	51 / 100	341 ms	14620 KiB

simurgh

#include <bits/stdc++.h>
#define f first
#define s second
#define ent '\n'

typedef long long ll;
using namespace std;

struct asd{
    int a, b, w, ca, cb;
};

int count_common_roads(const std::vector<int>& r);
int ask(vector<int> r){
    return count_common_roads(r);
}
const string out[2]={"NO\n","YES\n"};
const ll dx[]={0,1,0,-1,-1,1,1,-1};
const ll dy[]={1,0,-1,0,-1,1,-1,1};
const int mod=998244353;
const int md=1e9+7;
const int mx=3e5+12;

const bool T=0;

vector<pair<int,int>> g[mx];
vector<vector<int>> ord;
int col[505][505];
vector<int> vv,uu;
bool used[mx];
bool taken[mx];
bool del[mx];
int was[mx];
int need[mx];
int p[mx];
vector<int> cur;

int get(int x){
    if(p[x]==x){
        return x;
    }
    return p[x]=get(p[x]);
}

void check(vector<int> &cyc,int n){
    int m=vv.size();
    for(int i=0;i<n;i++){
        p[i]=i;
        used[i]=0;
    }
    for(auto i:cyc){
        used[vv[i]]=used[uu[i]]=1;
        p[get(vv[i])]=get(uu[i]);
    }
    vector<int> ost;
    for(int i=0;i<m;i++){
        if(need[i]==-1){
            continue;
        }
        if(get(vv[i])!=get(uu[i])){
            p[get(vv[i])]=get(uu[i]);
            ost.push_back(i);
        }
    }
    vector<int> A;
    int mn=1e9,mx=-1e9;
    for(int i:cyc){
        if(need[i]==1){
            A.push_back(-1);
            continue;
        }
        vector<int> os;
        os=ost;
        for(int j:cyc){
            if(i!=j){
                os.push_back(j);
            }
        }
        int x=ask(os);
        mn=min(mn, x);
        mx=max(mx, x);
        A.push_back(x);
    }
    for(auto &x:A){
        if(x==-1){
            x=mn;
        }
    }
    if(mn==mx){
        for(int i:cyc){
            if(need[i]!=1)need[i]=-1;
        }
        return;
    }
    for(int l=0;l<cyc.size();l++){
        int i=cyc[l];
        if(A[l]==mx){
            need[i]=-1;
        }
        else{
            need[i]=1;
        }
    }
}

void dfs(int v,int p){
    was[v]=1;
    cur.push_back(v);
    int cyc=-1;
    for(auto [to, i]:g[v]){
        if(to==p || need[i]==-1)continue;
        if(was[to]==1 && !taken[to]){
            cyc=to;
        }
        if(!was[to]){
            dfs(to, v);
        }
    }
    if(cyc!=-1){
        bool ok=0;
        int pos=cur.size()-1;
        for(int i=cur.size()-1;;i--){
            if(taken[cur[i]]){
                ok=1;
            }
            if(cur[i]==cyc){
                pos=i;
                break;
            }
        }
        if(ok){
            cur.pop_back();
            was[v]=2;
            return;
        }
        vector<int> cc;
        for(int i=cur.size()-1;i>=pos;i--){
            taken[cur[i]]=1;
            if(i>pos){
                cc.push_back(col[cur[i]][cur[i-1]]);
            }
        }
        cc.push_back(col[v][cyc]);
        ord.push_back(cc);
    }
    cur.pop_back();
    was[v]=2;
}

bool dec(int n,int m){
    ord.clear();
    cur.clear();
    for(int i=0;i<n;i++){
        was[i]=0;
        taken[i]=0;
    }
    for(int i=0;i<n;i++){
        if(!was[i]){
            dfs(i, -1);
        }
    }
    if(ord.size()==0){
        return 0;
    }
    for(auto &cyc:ord){
        check(cyc, n);
    }
    return 1;
}

vector<int> find_roads(int n, std::vector<int> u, std::vector<int> v){
    int m=u.size();
    vv=v, uu=u;
    for(int i=0;i<m;i++){
        g[v[i]].push_back({u[i], i});
        g[u[i]].push_back({v[i], i});
        col[v[i]][u[i]]=col[u[i]][v[i]]=i;
    }
    while(dec(n, m));
    vector<int> ans;
    for(int i=0;i<n;i++){
        p[i]=i;
    }
    for(int i=0;i<m;i++){
        if(need[i]==1){
            ans.push_back(i);
            p[get(v[i])]=get(u[i]);
        }
    }
    for(int i=0;i<m;i++){
        if(get(v[i])!=get(u[i]) && need[i]!=-1){
            ans.push_back(i);
            p[get(v[i])]=get(u[i]);
        }
    }
    return ans;
}

Compilation message (stderr)

simurgh.cpp: In function 'void check(std::vector<int>&, int)':
simurgh.cpp:95:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   95 |     for(int l=0;l<cyc.size();l++){
      |                 ~^~~~~~~~~~~
simurgh.cpp: In function 'void dfs(int, int)':
simurgh.cpp:110:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
  110 |     for(auto [to, i]:g[v]){
      |              ^

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