Submission #1013213

#	Time	Username	Problem	Language	Result	Execution time	Memory
1013213		boris_mihov	Comparing Plants (IOI20_plants)	C++17	27 / 100	1056 ms	102388 KiB

plants

#include "plants.h"
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <map>

typedef long long llong;
const int MAXN = 200000 + 10;
const int MAXLOG = 18;
const int INF  = 2e9;

int n, k;
struct SegmentTree
{
    struct Node
    {
        int min;
        int idx;
        int lazy;

        Node()
        {
            min = INF;
            idx = -1;
            lazy = 0;
        }

        friend Node operator + (const Node &left, const Node &right)
        {
            if (left.min < right.min)
            {
                return left;
            } else
            {
                return right;
            }
        }
    };

    Node tree[4*MAXN];
    void build(int l, int r, int node, int vals[])
    {
        if (l == r)
        {
            tree[node].min = vals[l];
            tree[node].idx = l;
            return;
        }

        int mid = l + r >> 1;
        build(l, mid, 2*node, vals);
        build(mid + 1, r, 2*node + 1, vals);
        tree[node] = tree[2*node] + tree[2*node + 1];
    }

    void push(int node, int l, int r)
    {
        if (tree[node].lazy == 0)
        {
            return;
        }

        tree[node].min += tree[node].lazy;
        if (l < r)
        {
            tree[2*node].lazy += tree[node].lazy;
            tree[2*node + 1].lazy += tree[node].lazy;
        }

        tree[node].lazy = 0;
    }

    void update(int l, int r, int node, int queryL, int queryR, int queryVal)
    {
        push(node, l, r);
        if (queryR < l || r < queryL)
        {
            return;
        }

        if (queryL <= l && r <= queryR)
        {
            tree[node].lazy = queryVal;
            push(node, l, r);
            return;
        }

        int mid = l + r >> 1;
        update(l, mid, 2*node, queryL, queryR, queryVal);
        update(mid + 1, r, 2*node + 1, queryL, queryR, queryVal);
        tree[node] = tree[2*node] + tree[2*node + 1];
    }
    
    Node query(int l, int r, int node, int queryL, int queryR)
    {
        push(node, l, r);
        if (queryL <= l && r <= queryR)
        {
            return tree[node];
        }

        Node result;
        int mid = l + r >> 1;
        if (queryL <= mid) result = result + query(l, mid, 2*node, queryL, queryR);
        if (mid + 1 <= queryR) result = result + query(mid + 1, r, 2*node + 1, queryL, queryR);
        return result;
    }

    void build(int r[])
    {
        build(1, n, 1, r);
    }

    void update(int l, int r, int val)
    {
        update(1, n, 1, l, r, val);
    }

    Node query(int l, int r)
    {
        return query(1, n, 1, l, r);
    }
};

struct Fenwick
{
    int tree[MAXN];
    void reset()
    {
        std::fill(tree + 1, tree + 1 + n, 0);
    }

    void update(int idx, int val)
    {
        for (; idx <= n ; idx += idx & (-idx))
        {
            tree[idx] += val;
        }
    }

    int query(int idx)
    {
        int res = 0;
        for (; idx ; idx -= idx & (-idx))
        {
            res += tree[idx];
        }

        return res;
    }

    int kth(int k)
    {
        int idx = 0;
        for (int lg = MAXLOG - 1 ; lg >= 0 ; --lg)
        {
            if (idx + (1 << lg) <= n && tree[idx + (1 << lg)] < k)
            {
                idx += (1 << lg);
                k -= tree[idx];
            }
        }

        return idx + 1;
    }
};

int h[2 * MAXN];
struct Sparse
{
    int sparse[MAXLOG + 1][2 * MAXN];
    void build(int jump[])
    {
        for (int i = 1 ; i <= 2 * n ; ++i)
        {
            sparse[0][i] = jump[i];
        }

        for (int lg = 1 ; (1 << lg) <= 2 * n ; ++lg)
        {
            for (int u = 1 ; u <= 2 * n ; ++u)
            {
                sparse[lg][u] = sparse[lg - 1][sparse[lg - 1][u]];
            }
        }
    }

    bool jumpLeft(int from, int to)
    {
        for (int lg = MAXLOG ; lg >= 0 ; --lg)
        {
            if (sparse[lg][from] != 0 && sparse[lg][from] >= to)
            {
                from = sparse[lg][from];
            }
        }

        if (from - k + 1 <= to && h[from] >= h[to]) return true;
        return false;
    }

    bool jumpRight(int from, int to)
    {
        for (int lg = MAXLOG ; lg >= 0 ; --lg)
        {
            if (sparse[lg][from] != 0 && sparse[lg][from] <= to)
            {
                from = sparse[lg][from];
            }
        }

        if (from + k - 1 >= to && h[from] >= h[to]) return true;
        return false;
    }
};

Fenwick fenwick;
SegmentTree tree;
Sparse sparsePrev;
Sparse sparseNext;

int r[MAXN];
int prev[2 * MAXN];
int next[2 * MAXN];
int ptrH;

void rec(int idx)
{
    while (true)
    {
        SegmentTree::Node res;
        if (idx > 1) res = res + tree.query(std::max(1, idx - k + 1), idx - 1);
        if (idx < k) res = res + tree.query(n - (k - idx) + 1, n);
        if (res.min == 0)
        {
            rec(res.idx);
        } else
        {
            break;
        }
    }

    h[idx] = ptrH--;
    tree.update(idx, idx, 2 * n);
    if (idx > 1) tree.update(std::max(1, idx - k + 1), idx, -1);
    if (idx < k) tree.update(n - (k - idx) + 1, n, -1);
}

std::map <int,int> toIndex;
void init(int K, std::vector <int> R) 
{
    k = K;
    n = R.size();
    for (int i = 1 ; i <= n ; ++i)
    {
        r[i] = R[i - 1];
    }

    ptrH = n;
    tree.build(r);
    while (ptrH > 0)
    {
        SegmentTree::Node res = tree.query(1, n);
        assert(res.min == 0);
        rec(res.idx);
    }

    for (int i = n + 1 ; i <= 2 * n ; ++i)
    {
        h[i] = h[i - n];
    }

    for (int i = 1 ; i < k ; ++i)
    {
        fenwick.update(h[i], 1);
    }

    for (int i = k ; i <= 2 * n ; ++i)
    {
        if (fenwick.query(h[i]) == 0)
        {
            prev[i] = 0;
        } else
        {
            prev[i] = toIndex[fenwick.kth(fenwick.query(h[i]))];
        }

        toIndex[h[i - k + 1]] = 0;
        toIndex[h[i]] = i;

        fenwick.update(h[i - k + 1], -1);
        fenwick.update(h[i], 1);
    }

    fenwick.reset();
    for (int i = 2 * n ; i > 2 * n - k + 1 ; --i)
    {
        fenwick.update(h[i], 1);
    }

    toIndex.clear();
    for (int i = 2 * n - k + 1 ; i >= 1 ; --i)
    {
        if (fenwick.query(h[i]) == 0)
        {
            next[i] = 0;
        } else
        {
            next[i] = toIndex[fenwick.kth(fenwick.query(h[i]))];
        }

        toIndex[h[i + k - 1]] = 0;
        toIndex[h[i]] = i;

        fenwick.update(h[i + k - 1], -1);
        fenwick.update(h[i], 1);
    }

    sparsePrev.build(prev);
    sparseNext.build(next);
}

int compare_plants(int x, int y) 
{
	x++; y++;
    if (sparsePrev.jumpLeft(x + n, y) || sparseNext.jumpRight(x, y)) return 1;
    if (sparsePrev.jumpLeft(y, x) || sparseNext.jumpRight(y, n + x)) return -1;
    assert(false);
    return 0;
}

Compilation message (stderr)

plants.cpp: In member function 'void SegmentTree::build(int, int, int, int*)':
plants.cpp:52:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   52 |         int mid = l + r >> 1;
      |                   ~~^~~
plants.cpp: In member function 'void SegmentTree::update(int, int, int, int, int, int)':
plants.cpp:90:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   90 |         int mid = l + r >> 1;
      |                   ~~^~~
plants.cpp: In member function 'SegmentTree::Node SegmentTree::query(int, int, int, int, int)':
plants.cpp:105:21: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
  105 |         int mid = l + r >> 1;
      |                   ~~^~~

• Subtask 1: 0 / 5
• Subtask 2: 14 / 14
• Subtask 3: 13 / 13
• Subtask 4: 0 / 17
• Subtask 5: 0 / 11
• Subtask 6: 0 / 15
• Subtask 7: 0 / 25