제출 #1061788

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1061788		Zicrus	고대 책들 (IOI17_books)	C++17	12 / 100	1 ms	604 KiB

books

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

typedef long long ll;

vector<ll> lnk;
vector<ll> mnUF, mxUF;

ll find(ll a) {
    if (lnk[a] != a) lnk[a] = find(lnk[a]);
    return lnk[a];
}

void unite(ll a, ll b) {
    a = find(a); b = find(b);
    if (a == b) return;
    lnk[a] = b;
    mnUF[b] = min(mnUF[b], mnUF[a]);
    mxUF[b] = max(mxUF[b], mxUF[a]);
}

ll minimum_walk(vector<int> p, int s) {
    ll n = p.size();
	ll res = 0;
    for (int i = 0; i < n; i++) res += abs(p[i] - i);
    if (res == 0) return 0;

    vector<bool> vst(n);
    vector<vector<ll>> cyc;
    vector<ll> mxCyc;
    vector<ll> cycId(n);
    for (int i = 0; i < n; i++) {
        if (vst[i] || p[i] == i) continue;
        cyc.push_back(vector<ll>());
        mxCyc.push_back(i);
 
        ll cur = i;
        do {
            cyc.back().push_back(cur);
            mxCyc.back() = max(mxCyc.back(), cur);
            cycId[cur] = cyc.size()-1;
            cur = p[cur];
            vst[cur] = true;
        } while (cur != i);
    }
    ll m = cyc.size();

    ll allMn = n, allMx = 0;
    for (int i = 0; i < m; i++) {
        allMn = min(allMn, cyc[i][0]);
        allMx = max(allMx, mxCyc[i]);
    }
    lnk = vector<ll>(m);
    mnUF = vector<ll>(m);
    mxUF = vector<ll>(m);
    for (int i = 0; i < m; i++) {
        lnk[i] = i;
        mnUF[i] = cyc[i][0];
        mxUF[i] = mxCyc[i];
    }
    for (int i = 0; i < m; i++) {
        for (int j = 0; j < m; j++) {
            if (cyc[i][0] < cyc[j][0] && mxCyc[i] > cyc[j][0] && mxCyc[i] < mxCyc[j]) {
                unite(i, j);
            }
        }
    }
    vector<pair<ll, ll>> lut; // -size, id
    for (int i = 0; i < m; i++) {
        mnUF[i] = mnUF[find(i)];
        mxUF[i] = mxUF[find(i)];
        if (i == lnk[i]) lut.push_back({mnUF[i] - mxUF[i], i});
    }
    sort(lut.begin(), lut.end());

    vector<ll> nxtDist(m, -1), nxtCyc(m);
    for (auto &e : lut) {
        ll i = e.second;
        ll left = mnUF[i], right = mxUF[i];
        ll dist = 0;
        while (left > allMn || right < allMx) {
            left = max(allMn, left-1);
            right = min(allMx, right+1);
            dist++;
            if (p[left] != left) {
                ll c = cycId[left];
                if (mnUF[c] < mnUF[i] && mxUF[c] > mxUF[i]) {
                    nxtDist[i] = dist;
                    nxtCyc[i] = c;
                    break;
                }
            }
            if (p[right] != right) {
                ll c = cycId[right];
                if (mnUF[c] < mnUF[i] && mxUF[c] > mxUF[i]) {
                    nxtDist[i] = dist;
                    nxtCyc[i] = c;
                    break;
                }
            }
        }
    }

    ll val = res, val1 = res;
    ll ptr = s;
    bool done = false;
    /*if (p[s] != s) {
        ll c = cycId[s];
        while (nxtDist[c] != -1) {
            throw;
            val += 2*nxtDist[c];
            c = nxtCyc[c];
        }
        ptr = allMn;
        done = true;
    }
    while (!done && ptr > allMn) {
        ptr = max(allMn, ptr-1);
        val += 2;
        if (p[ptr] != ptr) {
            ll c = cycId[ptr];
            while (nxtDist[c] != -1) {
                throw;
                val += 2*nxtDist[c];
                c = nxtCyc[c];
            }
            ptr = allMn;
            done = true;
            break;
        }
    }
    if (done) res = val;*/

    ptr = s;
    bool done1 = false;
    if (p[s] != s) {
        ll c = cycId[s];
        while (nxtDist[c] != -1) {
            throw;
            val1 += 2*nxtDist[c];
            c = nxtCyc[c];
        }
        ptr = allMx;
        done1 = true;
    }
    while (!done1 && ptr < allMx) {
        ptr++;
        val1 += 2;
        if (p[ptr] != ptr) {
            ll c = cycId[ptr];
            while (nxtDist[c] != -1) {
                throw;
                val1 += 2*nxtDist[c];
                c = nxtCyc[c];
            }
            ptr = allMx;
            done1 = true;
            break;
        }
    }
    if (done1) {
        if (done) res = min(res, val1);
        else res = val1;
    }

    ll lastMx = -1;
    for (int i = 1; i < m; i++) {
        if (lnk[i] != i) continue;
        if (lastMx == -1) {
            lastMx = mxUF[i];
            continue;
        }
        res += 2*max(0ll, mnUF[i] - lastMx);
    }

    return res;
}

컴파일 시 표준 에러 (stderr) 메시지

books.cpp: In function 'll minimum_walk(std::vector<int>, int)':
books.cpp:105:8: warning: unused variable 'val' [-Wunused-variable]
  105 |     ll val = res, val1 = res;
      |        ^~~

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