Submission #1060855

#	Time	Username	Problem	Language	Result	Execution time	Memory
1060855		onbert	Ancient Books (IOI17_books)	C++17	0 / 100	1 ms	4444 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
#define int long long
struct thing {
    int u, v, w;
    bool operator < (const thing &b) const {
        return w < b.w;
    }
};
const int maxn = 1e6 + 5, INF = 1e9;
int vis[maxn];
int last[maxn];

int fa[maxn];
int rt(int u) {
    if (fa[u]==u) return u;
    else return fa[u] = rt(fa[u]);
}

int minimum_walk(vector<int32_t> p, int32_t s) {
    int n = p.size();
    for (int i=0;i<n;i++) vis[i] = false;
    int ans = 0, cnt = 0;
    for (int i=0;i<n;i++) if (!vis[i]) {
        if (p[i]==i && i==s) {
            cnt++;
            vis[i] = cnt;
        }
        if (p[i]==i) continue;
        cnt++;
        int u = i;
        while (true) {
            // cout << cnt << endl;
            vis[u] = cnt;
            int v = p[u];
            ans += abs(v-u);
            if (v==i) break;
            u = v;
        }
    }
    last[n] = n;
    vector<thing> edge;
    for (int i=n-1;i>=0;i--) {
        if (p[i]!=i || i==s) {
            last[i] = i;
            if (last[i+1]!=n && vis[last[i+1]]!=vis[i]) edge.push_back({vis[i], vis[last[i+1]], last[i+1] - i});
            // cout << i << " " << last[i+1] << " " << vis[last[i+1]] << " " << vis[i] << endl;
        } else last[i] = last[i+1];
    }
    for (int i=1;i<=cnt;i++) fa[i] = i;
    sort(edge.begin(), edge.end());
    for (auto [u, v, w]:edge) {
        if (rt(u)==rt(v)) continue;
        ans += w*2;
        fa[rt(u)] = rt(v);
    }
    return ans;
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 10
• Subtask 3: 0 / 28
• Subtask 4: 0 / 20
• Subtask 5: 0 / 30