Submission #1086666

#	Time	Username	Problem	Language	Result	Execution time	Memory
1086666		nathan4690	Passport (JOI23_passport)	C++17	0 / 100	12 ms	23956 KiB

passport

#include <bits/stdc++.h>
#define ll long long
#define pll pair<ll,ll>
#define ld long double
#define el cout << '\n'
#define f1(i,n) for(ll i=1;i<=n;i++)
#define __file_name ""
using namespace std;
const ll maxn = 1e6+5, inf=1e18;

ll n, rpos[maxn], l, r, lf[maxn], rt[maxn], q, x, d[maxn], d1[maxn],dn[maxn];
vector<pair<ll,ll>> G[maxn];
bool vis[maxn];
priority_queue<pll, vector<pll>, greater<pll>> pq;

void addEdge(ll u, ll v, ll w){
    // cout << u << " -> " << v << " w = " << w;el;
    G[u].push_back({v, w});
}

void build(ll idx, ll l, ll r){
    if(l == r){
        rpos[l] = idx;
        return;
    }
//    addEdge(idx, idx*2, 0);
//    addEdge(idx, idx*2+1, 0);
    addEdge(idx*2, idx, 0);
    addEdge(idx*2+1, idx, 0);
    ll mid = (l+r)/2;
    build(idx*2, l, mid);
    build(idx*2+1, mid+1, r);
}

void addSeg(ll idx, ll l, ll r, ll u, ll v, ll tar, ll w){
    // connects tar -> [u,v] if not rev
    if(r < u || v < l) return;
    if(u <= l && r <= v){
        addEdge(idx, tar, w);
        return;
    }
    ll mid = (l+r)/2;
    addSeg(idx*2, l, mid, u, v, tar, w);
    addSeg(idx*2+1, mid+1, r, u, v, tar, w);
}

void calc(){
    while(!pq.empty()){
        pair<ll,ll> item = pq.top();
        pq.pop();
        ll dist = item.first, u = item.second;
        if(dist != d[u]) continue;
        vis[u] = true;
        for(pair<ll,ll> e: G[u]){
            ll c = e.first, w = e.second;
            if(d[u] + w < d[c]){
                // cout << u << " -> " << c << " changed: " << d[u] + w;el;
                d[c] = d[u] + w;
                pq.push({d[c], c});
            }
        }
    }
}

void dijkstra(ll s){
    d[0] = inf;
    f1(i,4*n) d[i] = inf;
    d[s] = 0ll;
    pq.push({d[s], s});
    calc();
}

int main(){
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

    if(fopen(__file_name ".inp", "r")){
        freopen(__file_name ".inp","r",stdin);
        freopen(__file_name ".out","w",stdout);
    }
    // code here
    cin >> n;
    build(1, 1, n);
    f1(i,n){
        cin >> l >> r;
        lf[i] = l; rt[i] = r;
        if(l != i){
            addSeg(1,1,n,l,i-1,rpos[i],1);
        }
        if(i != r){
            addSeg(1,1,n,i+1,r,rpos[i],1);
        }
    }
    dijkstra(rpos[1]);
    f1(i,n) d1[i] = d[rpos[i]];
    dijkstra(rpos[n]);
    f1(i,n) dn[i] = d[rpos[i]];
    f1(i,4*n) d[i] = inf;
    f1(i,n) {
        // cout << i << " = " << d1[i] << ' ' << dn[i];el;
        d[rpos[i]] = d1[i] + dn[i] - (lf[i] == 1 && rt[i] == n);
        pq.push({d[rpos[i]], rpos[i]});
    }
    calc();
    cin >> q;
    while(q--){
        cin >> x;
        // cout << x << " = " << rpos[x];el;
        cout << (d[rpos[x]] < inf ? d[rpos[x]] : -1);el;
    }
    return 0;
}

Compilation message (stderr)

passport.cpp: In function 'int main()':
passport.cpp:77:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   77 |         freopen(__file_name ".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
passport.cpp:78:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |         freopen(__file_name ".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 6
• Subtask 2: 0 / 16
• Subtask 3: 0 / 24
• Subtask 4: 0 / 8
• Subtask 5: 0 / 46