제출 #930598

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
930598		Faisal_Saqib	Joker (BOI20_joker)	C++17	0 / 100	101 ms	31676 KiB

Joker

#include <bits/stdc++.h>
using namespace std;
const int M=2e5+1;
int n,m,q;
bool mark[M],vis[M],cycle=0;
int val[M],par[M],h[M];
vector<int> com[M];
vector<pair<int,int>> ma[M],query,edges;
int mx_r_for_l[M];
bool found=0;
void dfs(int x)
{
    vis[x]=1;
    for(auto [y,ind]:ma[x])
    {
        if(mark[ind])
            continue;
        if(!vis[y])
        {
            val[y]=(val[x]+1)%2;
            dfs(y);
        }
        else if((val[y]+1)%2!=val[x])
        {
            found=1;
        }
    }
}
bool check(int l,int r)
{
    // cout<<"Check "<<l<<' '<<r<<endl;
    for(int i=1;i<=n;i++)
        vis[i]=0;
    for(int i=0;i<m;i++)
        mark[i]=(l<=i and i<=r);
    found=0;
    for(int i=1;i<=n;i++)
    {
        if(!vis[i])
        {
            dfs(i);
        }
    }
    // cout<<"Answer "<<found<<endl;
    return found;
}
void init(){
    cycle=0;
    for(int i=1;i<=n;i++)
    {
        h[i]=0;
        par[i]=i;
        com[i]={i};
    }
}
void add_edge(int ind)
{
    int u=edges[ind].first;
    int v=edges[ind].second;
    int pu=par[u];
    int pv=par[v];
    // cout<<"Hola "<<u<<' '<<v<<endl;
    // cout<<pu<<' '<<pv<<endl;
    if(pu==pv)
    {
        if(h[u]==h[v])
        {
            cycle=1;
        }
    }
    else{
        int cp=(h[u]!=h[v]);
        u=pu;
        v=pv;
        if(com[u].size()>com[v].size())
            swap(u,v);
        for(auto ver:com[u])
        {
            com[v].push_back(ver);
            par[ver]=v;
            h[ver]=(h[ver]+cp)%2;
        }
        com[u].clear();
    }
}
int main()
{
    cin.tie(0);
    cout.tie(0);
    ios::sync_with_stdio(0);
 
    cin>>n>>m>>q;
    for(int i=0;i<m;i++)
    {
        int a,b;
        cin>>a>>b;
        // cout<<i+1<<"th edge is "<<a<<' '<<b<<endl;
        ma[a].push_back({b,i});
        ma[b].push_back({a,i});
        edges.push_back({a,b});
    }
    vector<int> difl={-1};
    for(int lp=0;lp<q;lp++)
    {
        int l,r;
        cin>>l>>r;
        l--;
        r--;
        query.push_back({l,r});
        difl.push_back(l);
    }
    sort(begin(difl),end(difl));
    for(int i=1;i<difl.size();i++)
    {
        if(difl[i-1]!=difl[i])
        {
            int l=difl[i];
            int r=m;
            init();
            for(int p=0;p<l;p++)
                add_edge(p);
            while(!cycle)
            {
                r--;
                add_edge(r);
            }
            mx_r_for_l[l]=r-1;
        }
    }
    for(auto [l,r]:query)
    {
        if(mx_r_for_l[l]>=r)
        {
            // cout<<"Query  "<<l<<' '<<r<<endl;
            cout<<"YES"<<'\n';
        }
        else{
            cout<<"NO"<<'\n';
        }
    }
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

Joker.cpp: In function 'int main()':
Joker.cpp:113:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  113 |     for(int i=1;i<difl.size();i++)
      |                 ~^~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 8
• Subtask 3: 0 / 25
• Subtask 4: 0 / 10
• Subtask 5: 0 / 22
• Subtask 6: 0 / 29