Submission #1060076

#	Time	Username	Problem	Language	Result	Execution time	Memory
1060076		mindiyak	Joker (BOI20_joker)	C++14	0 / 100	2057 ms	18912 KiB

Joker

#pragma GCC optimize("O1,O2,O3,Ofast,unroll-loops")
#include <bits/stdc++.h>
#include <string>
#include <iostream>
#include <cmath>
#include <numeric>
#include <stack>
#include <queue>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<int, int> pi;
typedef pair<ll, ll> pl;
typedef pair<ld, ld> pd;
typedef vector<int> vi;
typedef vector<bool> vb;
typedef vector<vector<int>> vvi;
typedef vector<vector<pi>> vvpi;
typedef vector<ld> vd;
typedef vector<long long> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
#define FOR(i, a, b) for (int i = a; i < (b); i++)
#define F0R(i, a) for (int i = 0; i < (a); i++)
#define FORd(i, a, b) for (int i = (b)-1; i >= a; i--)
#define F0Rd(i, a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto &a : x)
#define uid(a, b) uniform_int_distribution<int>(a, b)(rng)
#define len(x) (int)(x).size()
#define mp make_pair
#define pb push_back
#define F first
#define nl endl
#define S second
#define lb lower_bound
#define ub upper_bound
#define aint(x) x.begin(), x.end()
#define raint(x) x.rbegin(), x.rend()
#define ins insert
const int M = 1e9+7;
void init(string name)
{
    freopen((name + ".in").c_str(), "r", stdin);
    freopen((name + ".out").c_str(), "w", stdout);
}
void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
}

int n,m,q;
vector<vpi> paths(2e5+10,vpi());
vi visited(2e5+10,0);
bool solved = 0;

void dfs(int pos,int prev,int len,int l,int r){
    if(solved)return;
    if(visited[pos] > 0){
        // cerr << pos << " " << visited[pos] << " " << len << endl;
        if((len-visited[pos])%2 == 1)solved = 1;
        return;
    }

    visited[pos] = len;

    for(pi a:paths[pos]){
        if(a.F == prev)continue;
        if(l <= a.S && a.S <= r)continue;
        dfs(a.F,pos,len+1,l,r);
    }
}

void solve()
{
    cin >> n >> m >> q;
    FOR(i,0,m){
        int a,b;cin >> a >> b;
        paths[a].pb({b,i+1});
        paths[b].pb({a,i+1});
    }

    FOR(i,0,q){
        int a,b;cin >> a >> b;
        visited = vi(2e5+10,0);
        FOR(i,1,n+1){
            if(solved)break;
            if(visited[i]!=0)continue;
            dfs(i,-1,1,a,b);
        }

        // FOR(j,1,n+1)cerr << visited[j] << " ";
        // cerr << endl;

        if(solved) cout << "YES" << endl;
        else cout << "NO" << endl;
    }
}   
 
 
int main()
{
    fastIO();
    // init("test");
    int t = 1;
    // cin >> t;
    while (t--)
        solve();
    return 0;
}

Compilation message (stderr)

Joker.cpp: In function 'void init(std::string)':
Joker.cpp:44:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   44 |     freopen((name + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Joker.cpp:45:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |     freopen((name + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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