Submission #421958

#	Time	Username	Problem	Language	Result	Execution time	Memory
421958		MarcoMeijer	Ancient Books (IOI17_books)	C++17	22 / 100	2080 ms	39636 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;

// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e9
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
#define sz size()
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cout << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }

ll minimum_walk(vi p, int s) {
    int n = p.size();
    ll ans = 0;
    vi visited; visited.assign(n,0);
    vi left; left.assign(n,0);
    vi right; right.assign(n,0);
    vi rightInt, leftInt; rightInt.assign(n,0); leftInt.assign(n,0);
    vi rightEmpty, leftEmpty; rightEmpty.assign(n,1); leftEmpty.assign(n,1);

    RE(i,n)
        ans += (ll)abs(i-p[i]);

    RE(i,n) {
        if(visited[i]) continue;
        left[i] = i, right[i] = i;
        if(i == p[i]) continue;
        int u = p[i];
        while(u != i) {
            visited[u] = 1;
            left [i] = min(left [i], u);
            right[i] = max(right[i], u);
            u = p[u];
        }
        u = p[i];
        while(u != i) {
            left [u] = left [i];
            right[u] = right[i];
            u = p[u];
        }
    }

    REV(i,s,n) {
        if(i != n-1)
            rightInt[i] = rightInt[i+1];
        if(i != n-1)
            rightEmpty[i] = rightEmpty[i+1];
        if(left[i] <= s)
            rightInt[i] = 1;
        if(left[i] != right[i])
            rightEmpty[i] = 0;
    }
    REP(i,0,s+1) {
        if(i != 0)
            leftInt[i] = leftInt[i-1];
        if(i != n-1)
            leftEmpty[i] = leftEmpty[i-1];
        if(right[i] >= s)
            leftInt[i] = 1;
        if(left[i] != right[i])
            leftEmpty[i] = 0;
    }

    function<int(int)> getLeftSize  = [&](int x) {
        static vi mem(n,-1);
        if(mem[x] != -1)
            return mem[x];

        int i = x;
        int res = 0;
        int leftSide = x;
        int firstInt = INF;
        while(i-- > 0) {
            if(!leftInt[i])
                return mem[x] = leftEmpty[i] ? int(INF) : 1;
            if(i < leftSide)
                res++;
            if(right[i] >= s)
                return mem[x] = res;
            if(firstInt == INF && left[i] != right[i]) {
                firstInt = res;
            }
            leftSide = min(leftSide, left[i]);
        }
        return mem[x] = firstInt;
    };
    function<int(int)> getRightSize = [&](int x) {
        static vi mem(n,-1);
        if(mem[x] != -1)
            return mem[x];

        int i = x;
        int res = 0;
        int rightSide = i;
        int firstInt = INF;
        while(i++ < n-1) {
            if(!rightInt[i])
                return mem[x] = rightEmpty[i] ? int(INF) : 1;
            if(i > rightSide)
                res++;
            if(left[i] <= s)
                return mem[x] = res;
            if(firstInt == INF && left[i] != right[i]) {
                firstInt = res;
            }
            rightSide = max(rightSide, right[i]);
        }
        return mem[x] = firstInt;
    };

    int ls=s, rs=s, nls=s, nrs=s;
    queue<int> q; q.push(s);

    while(true) {
        while(!q.empty()) {
            int i = q.front(); q.pop();
            if(i == p[i]) continue;
            int u = p[i];
            while(u != i) {
                while(ls > u) q.push(--ls);
                while(rs < u) q.push(++rs);

                u = p[u];
            }
        }

        if(nls < ls || nrs > rs) {
            while(ls > nls) {
                q.push(--ls);
                ans += 2ll;
                if(left[ls] != right[ls])
                    break;
            }
            while(rs < nrs) {
                q.push(++rs);
                ans += 2ll;
                if(left[rs] != right[rs])
                    break;
            }
            continue;
        }

        int leftSize = getLeftSize(ls), rightSize = getRightSize(rs);

        if(leftSize == INF && rightSize == INF)
            break;
        if(leftSize < rightSize) {
            nls = ls - leftSize;
        } else {
            nrs = rs + rightSize;
        }
    }

	return ans;
}

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