Submission #283943

#	Time	Username	Problem	Language	Result	Execution time	Memory
283943		ToMmyDong	Ancient Books (IOI17_books)	C++11	0 / 100	1 ms	1280 KiB

books

#include "books.h"
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
#define SZ(i) int(i.size())
#define ALL(i) i.begin(), i.end()
#define MEM(i,a) memset(i, (a), sizeof(i))
#define X first
#define Y second
#define eb emplace_back
#define pb push_back
#ifdef tmd
#define debug(...) fprintf(stderr,"#%d-(%s)=",__LINE__,#__VA_ARGS__);_do(__VA_ARGS__);
template<typename T> void _do (T &&x) {cerr<<x<<endl;}
template<typename T, typename ...S> void _do(T &&x, S &&...y) {cerr<<x<<", ";_do(y...);}
template<typename IT> ostream& __printRng (ostream &os, IT bg, IT ed) {
    for (IT it=bg; it!=ed; it++) {
        if (it!=bg) os << "," << *it;
        else os << "{" << *it;
    }
    return os << "}";
}
template<typename T> ostream &operator << (ostream &os, const pair<T,T> &v) {
    return os <<"{"<<v.X<<","<<v.Y<<"}";
}
template<typename T> ostream &operator << (ostream &os, const vector<T> &v) {
    return __printRng(os, ALL(v));
}
template<typename T> ostream &operator << (ostream &os, const set<T> &v) {
    return __printRng(os, ALL(v));
}
#else
#define debug(...)
#endif

const int MAXN = 1000006;

bool vis[MAXN];
vector<int> to;


long long bf_minimum_walk(std::vector<int> p, int s) {
    set<vector<int> > vis;
    queue<vector<int> > bfs;
    int n = SZ(p);
    vector<int> targ(n);
    iota(ALL(targ), 0);
    targ.eb(-1);
    targ.eb(s);

    int ans = 0;
    p.eb(-1);
    p.eb(s);
    bfs.emplace(p);
    vis.insert(p);
    swap(p[s], p[n]);
    vis.insert(p);
    bfs.emplace(p);
    while (bfs.size()) {
        int sz = bfs.size();
        for (int _i=0; _i<sz; _i++) {
            vector<int> cur = bfs.front();
            bfs.pop();
            if (cur == targ) return ans;

            vector<int> mv = {cur[n+1]-1, cur[n+1]+1};
            for (int i : mv) {
                if (i < 0 || i >= n) continue;
                vector<int> nw = cur;
                nw[n+1] = i;
                if (vis.count(nw) == 0) {
                    vis.insert(nw);
                    bfs.emplace(nw);
                }
                swap(nw[i], nw[n]);
                if (vis.count(nw) == 0) {
                    vis.insert(nw);
                    bfs.emplace(nw);
                }
            }
        }
        ans++;
    }
	return -1;
}

void dfs (int nd, int &mn, int &mx, ll &sum) {
    vis[nd] = true;
    mn = min(mn, nd);
    mx = max(mx, nd);
    if (vis[to[nd]] == 0) dfs(to[nd], mn, mx, sum);
    sum += abs(to[nd] - nd);
}

long long minimum_walk(std::vector<int> p, int s) {
    int n = SZ(p);
    to = p;

    MEM(vis, 0);
    vector<int> from(n);
    for (int i=0; i<n; i++) {
        from[to[i]] = i;
    }

    vector<pii> res;
    ll ans = 0;
    for (int i=0; i<n; i++) {
        if (!vis[i]) {
            int mn = n, mx = -1;
            ll sum = 0;
            dfs(i, mn, mx, sum);
            if (mn != mx) res.eb(mn, mx);
            ans += sum;
        }
    }
    debug(res);

    sort(ALL(res));
    int lst = 0;
    int comp = 0;
    int L = 0;
    int lb = 0; 
    for (auto pa : res) {
        if (pa.X > lst) {
            comp += pa.X - lst;
            debug(pa, to[pa.X]);
            //assert(pa.X == lst+1);
            L = pa.X;
            ans -= abs(to[pa.X]- pa.X);
            lb = abs(to[pa.X]- pa.X);
        }
        lst = max(lst, pa.Y);
    }
    ans += lb;

    debug(ans, comp, L);
    ll me = ans + comp + L;
    if (comp == 0) return 0;

    return me;
}

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