Submission #737579

#	Time	Username	Problem	Language	Result	Execution time	Memory
737579		GrindMachine	Bubble Sort 2 (JOI18_bubblesort2)	C++17	100 / 100	3141 ms	55264 KiB

bubblesort2

// Om Namah Shivaya

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x, y) ((x + y - 1) / (y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i, n) for(int i = 0; i < n; ++i)
#define rep1(i, n) for(int i = 1; i <= n; ++i)
#define rev(i, s, e) for(int i = s; i >= e; --i)
#define trav(i, a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a, b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a, b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
edi: http://s3-ap-northeast-1.amazonaws.com/data.cms.ioi-jp.org/open-2018/2018-open-bubblesort2-sol-en.pdf
https://codeforces.com/blog/entry/61340?#comment-452982
(read edi of linked usaco problem, it contains the proof for the approach mentioned in the joi edi)

*/

#include "bubblesort2.h"

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

template<typename T>
struct fenwick {
    int siz;
    vector<T> tree;

    fenwick(int n) {
        siz = n;
        tree = vector<T>(n + 1);
    }

    int lsb(int x) {
        return x & -x;
    }

    void build(vector<T> &a, int n) {
        for (int i = 1; i <= n; ++i) {
            int par = i + lsb(i);
            tree[i] += a[i];

            if (par <= siz) {
                tree[par] += tree[i];
            }
        }
    }

    void pupd(int i, T v) {
        i++;

        while (i <= siz) {
            tree[i] += v;
            i += lsb(i);
        }
    }

    T sum(int i) {
        i++;

        T res = 0;

        while (i) {
            res += tree[i];
            i -= lsb(i);
        }

        return res;
    }

    T query(int l, int r) {
        if (l > r) return 0;
        T res = sum(r) - sum(l - 1);
        return res;
    }
};

template<typename T>
struct lazysegtree {
    /*=======================================================*/

    struct data {
        int a;
    };

    struct lazy {
        int a;
    };

    data d_neutral = { -inf1};
    lazy l_neutral = {0};

    void merge(data &curr, data &left, data &right) {
        curr.a = max(left.a, right.a);
    }

    void create(int x, int lx, int rx, T v) {
        tr[x].a = v;
    }

    void modify(int x, int lx, int rx, T v) {
        if (v.ff == 1) {
            // set
            tr[x].a = v.ss;
        }
        else {
            // add
            lz[x].a = v.ss;
        }
    }

    void propagate(int x, int lx, int rx) {
        ll v = lz[x].a;
        if (!v) return;

        tr[x].a += v;

        if (rx - lx > 1) {
            lz[2 * x + 1].a += v;
            lz[2 * x + 2].a += v;
        }

        lz[x] = l_neutral;
    }

    /*=======================================================*/

    int siz = 1;
    vector<data> tr;
    vector<lazy> lz;

    lazysegtree() {

    }

    lazysegtree(int n) {
        while (siz < n) siz *= 2;
        tr.assign(2 * siz, d_neutral);
        lz.assign(2 * siz, l_neutral);
    }

    void build(vector<T> &a, int n, int x, int lx, int rx) {
        if (rx - lx == 1) {
            if (lx < n) {
                create(x, lx, rx, a[lx]);
            }

            return;
        }

        int mid = (lx + rx) / 2;

        build(a, n, 2 * x + 1, lx, mid);
        build(a, n, 2 * x + 2, mid, rx);

        merge(tr[x], tr[2 * x + 1], tr[2 * x + 2]);
    }

    void build(vector<T> &a, int n) {
        build(a, n, 0, 0, siz);
    }

    void rupd(int l, int r, T v, int x, int lx, int rx) {
        propagate(x, lx, rx);

        if (lx >= r or rx <= l) return;
        if (lx >= l and rx <= r) {
            modify(x, lx, rx, v);
            propagate(x, lx, rx);
            return;
        }

        int mid = (lx + rx) / 2;

        rupd(l, r, v, 2 * x + 1, lx, mid);
        rupd(l, r, v, 2 * x + 2, mid, rx);

        merge(tr[x], tr[2 * x + 1], tr[2 * x + 2]);
    }

    void rupd(int l, int r, T v) {
        rupd(l, r + 1, v, 0, 0, siz);
    }

    data query(int l, int r, int x, int lx, int rx) {
        propagate(x, lx, rx);

        if (lx >= r or rx <= l) return d_neutral;
        if (lx >= l and rx <= r) return tr[x];

        int mid = (lx + rx) / 2;

        data curr;
        data left = query(l, r, 2 * x + 1, lx, mid);
        data right = query(l, r, 2 * x + 2, mid, rx);

        merge(curr, left, right);
        return curr;
    }

    data query(int l, int r) {
        return query(l, r + 1, 0, 0, siz);
    }
};

vector<int> countScans(vector<int> a, vector<int> qx, vector<int> qv) {
    int n = sz(a);
    int q = sz(qx);

    vector<pii> b;
    rep(i, n) {
        b.pb({a[i], i});
    }
    rep(i, q) {
        b.pb({qv[i], qx[i]});
    }

    sort(all(b));
    b.resize(unique(all(b)) - b.begin());
    int siz = sz(b);

    auto get_ind = [&](pii p) {
        return lower_bound(all(b), p) - b.begin();
    };

    lazysegtree<pii> st(siz + 5);
    fenwick<int> fenw(siz + 5);

    rep(i, n) {
        int ind = get_ind({a[i], i});
        st.rupd(ind, ind, {1, i});
        fenw.pupd(ind, 1);
    }

    rep(i, n) {
        int ind = get_ind({a[i], i});
        st.rupd(ind + 1, siz, {2, -1});
    }

    vector<int> ans(q);

    rep(id, q) {
        int i = qx[id];
        int v = qv[id];

        int ind1 = get_ind({a[i], i});
        st.rupd(ind1, ind1, {1, -inf1});
        st.rupd(ind1, siz, {2, 1});
        fenw.pupd(ind1, -1);

        a[i] = v;

        int ind2 = get_ind({a[i], i});
        int smaller = fenw.query(0, ind2 - 1);
        st.rupd(ind2, ind2, {1, i - smaller});
        st.rupd(ind2 + 1, siz, {2, -1});
        fenw.pupd(ind2, 1);

        ans[id] = st.query(0, siz).a;
    }

    return ans;
}

• Subtask 1: 17 / 17
• Subtask 2: 21 / 21
• Subtask 3: 22 / 22
• Subtask 4: 40 / 40