Submission #731297

# Submission time Handle Problem Language Result Execution time Memory
731297 2023-04-27T09:06:12 Z danikoynov Sky Walking (IOI19_walk) C++14
33 / 100
213 ms 20796 KB
#include "walk.h"
#include <bits/stdc++.h>

using namespace std;
typedef long long ll;

const int maxn = 1e5 + 10;

struct skywalk
{
    int left, right;
    ll height;

    skywalk(int _left = 0, int _right = 0, ll _height = 0)
    {
        left = _left;
        right = _right;
        height = _height;
    }
}sky[maxn];

bool cmp(const skywalk &sk1, const skywalk &sk2)
{
    return sk1.height < sk2.height;
}

const ll inf = 1e18;
struct node
{
    ll down_sum, up_sum;

    node(ll _down_sum = inf, ll _up_sum = inf)
    {
        down_sum = _down_sum;
        up_sum = _up_sum;
    }
};

node merge_nodes(node lf, node rf)
{
    node nd;
    nd.down_sum = min(lf.down_sum, rf.down_sum);
    nd.up_sum = min(lf.up_sum, rf.up_sum);
    return nd;
}

node tree[4 * maxn];
int is_active[maxn];
ll dp[maxn];
void toggle(int root, int left, int right, int pos)
{
    if (left == right)
    {
        is_active[left] ^= 1;
        ///cout << root << " : " << left << " : " << right << " : " << pos << " " << is_active[left] << endl;
        if (is_active[left])
        {
            tree[root].down_sum = - sky[left].height + dp[left];
            tree[root].up_sum = sky[left].height + dp[left];
            ///cout << "activate " << left << " " << sky[left].height << endl;
        }
        else
        {
            tree[root] = node();
        }
        return;
    }

    int mid = (left + right) / 2;

    if (pos <= mid)
        toggle(root * 2, left, mid, pos);
    else
        toggle(root * 2 + 1, mid + 1, right, pos);


    tree[root] = merge_nodes(tree[root * 2], tree[root * 2 + 1]);
    ///cout << "here " << left << " " << right << " " << tree[root].up_sum << endl;
}

node query(int root, int left, int right, int qleft, int qright)
{
    if (left > qright || right < qleft)
    return node();

    if (left >= qleft && right <= qright)
        return tree[root];

    int mid = (left + right) / 2;
    return merge_nodes(query(root * 2, left, mid, qleft, qright),
                       query(root * 2 + 1, mid + 1, right, qleft, qright));
}

int n, m;
ll x[maxn], h[maxn];
vector < pair < int, int > > upd[maxn];

ll state[100][100];
bool intersects(int idx, int pos)
{
    if (sky[idx].left <= pos && sky[idx].right >= pos && sky[idx].height <= h[pos])
        return true;
    return false;
}

void relax_state(int i)
{
                for (int p1 = 0; p1 < m; p1 ++)
            {
                if (!intersects(p1, i))
                    continue;
                for (int p2 = 0; p2 < m; p2 ++)
                {
                    if (!intersects(p2, i))
                        continue;
                    state[i][p2] = min(state[i][p2], state[i][p1] + abs(sky[p1].height - sky[p2].height));
                }
            }
}
long long min_distance(vector<int> X, vector<int> H, vector<int> l, vector<int> r, vector<int> y, int s, int g)
{
    n = X.size();
    m = l.size();
    for (int i = 0; i < n; i ++)
        x[i] = X[i], h[i] = H[i];
    for (int i = 0; i < m; i ++)
    {
        sky[i] = skywalk(l[i], r[i], y[i]);
    }
    sort(sky, sky + m, cmp);

    if (n <= 50 && m <= 50)
    {
        if (s > g)
            swap(s, g);

            /**cout << "skywalk" << endl;
            for (int j = 0; j < m; j ++)
            {
                cout << j << " : " << sky[j].left << " " << sky[j].right << " " << sky[j].height << endl;
            }
            cout << "------------" << endl;*/
            for (int i = 0; i < n; i ++)
                for (int j = 0; j < m; j ++)
                state[i][j] = inf;
        for (int j = 0; j < m; j ++)
        {
            if (intersects(j, s))
                state[s][j] = sky[j].height;
        }

        for (int i = s - 1; i >= 0; i --)
        {
            for (int j = i + 1; j <= s; j ++)
            {
                for (int p = 0; p < m; p ++)
                {
                    if (intersects(p, i) && intersects(p, j))
                    {
                        state[i][p] = min(state[i][p], state[j][p] + abs(x[j] - x[i]));
                    }
                }
            }
            relax_state(i);
        }

        /**for (int j = 0; j < m; j ++)
            cout << state[s][j] << " ";
        cout << endl;*/

        for (int i = 0; i < n; i ++)
        {
                        for (int j = 0; j < i; j ++)
            {
                for (int p = 0; p < m; p ++)
                {
                    if (intersects(p, i) && intersects(p, j))
                    {
                        state[i][p] = min(state[i][p], state[j][p] + abs(x[j] - x[i]));
                    }
                }
            }


            relax_state(i);
        }

        /**for (int i = n - 1; i >= g; i --)
        {
            for (int j = n - 1; j > i; j --)
            {
                for (int p = 0; p < m; p ++)
                {
                    if (intersects(p, i) && intersects(p, j))
                    {
                        state[i][p] = min(state[i][p], state[j][p] + abs(x[j] - x[i]));
                    }
                }
            }

            relax_state(i);
        }*/

        ll ans = inf;
        for (int j = 0; j < m; j ++)
        {
            if (state[g][j] != inf)
                ans = min(ans, state[g][j] + sky[j].height);
        }
        if (ans == inf)
            return -1;
        return ans;
    }
    if (s != 0 || g != n - 1)
        return 0;

         for (int i = 0; i < m; i ++)
        {
            upd[sky[i].left].push_back({i, 1});
        }
        for (int i = 0; i < m; i ++)
        {

            upd[sky[i].right].push_back({i, -1});
        }



    for (pair < int, int > cur : upd[s])
    {
        dp[cur.first] = sky[cur.first].height;
        toggle(1, 0, m - 1, cur.first);
        ///cout << "here" << endl;
    }


    ///cout << tree[1].up_sum << endl;
    for (int i = 1; i < g; i ++)
    {
        for (pair < int, int > cur : upd[i])
        {

            if (cur.second == 1)
            {
                node under = node(), above = node();
                if (cur.first != 0)
                    under = query(1, 0, m - 1, 0, cur.first - 1);
                if (cur.first != m - 1)
                    above = query(1, 0, m - 1, cur.first + 1, m - 1);
            //cout << under.down_sum << " " << above.up_sum << endl;

                if (under.down_sum == inf && above.up_sum == inf)
                    dp[cur.first] = inf;
                else
                    dp[cur.first] = min(sky[cur.first].height + under.down_sum, above.up_sum - sky[cur.first].height);
                ///cout << cur.first << " :: " << dp[cur.first] << endl;
            }


            toggle(1, 0, m - 1, cur.first);
        }
    }

    node ans = tree[1];
    if (ans.up_sum == inf)
        return -1;
    return ans.up_sum + x[g] - x[s];
}

Compilation message

walk.cpp: In function 'long long int min_distance(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, int, int)':
walk.cpp:134:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
  134 |         if (s > g)
      |         ^~
walk.cpp:143:13: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
  143 |             for (int i = 0; i < n; i ++)
      |             ^~~
# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 10452 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 10452 KB Output isn't correct
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 63 ms 13948 KB Output is correct
2 Correct 133 ms 16372 KB Output is correct
3 Correct 159 ms 16960 KB Output is correct
4 Correct 213 ms 20620 KB Output is correct
5 Correct 173 ms 20344 KB Output is correct
6 Correct 172 ms 20608 KB Output is correct
7 Correct 113 ms 17588 KB Output is correct
8 Correct 196 ms 20264 KB Output is correct
9 Correct 194 ms 20792 KB Output is correct
10 Correct 120 ms 19624 KB Output is correct
11 Correct 15 ms 11988 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 63 ms 13948 KB Output is correct
2 Correct 133 ms 16372 KB Output is correct
3 Correct 159 ms 16960 KB Output is correct
4 Correct 213 ms 20620 KB Output is correct
5 Correct 173 ms 20344 KB Output is correct
6 Correct 172 ms 20608 KB Output is correct
7 Correct 113 ms 17588 KB Output is correct
8 Correct 196 ms 20264 KB Output is correct
9 Correct 194 ms 20792 KB Output is correct
10 Correct 120 ms 19624 KB Output is correct
11 Correct 15 ms 11988 KB Output is correct
12 Correct 131 ms 16972 KB Output is correct
13 Correct 171 ms 20636 KB Output is correct
14 Correct 157 ms 20352 KB Output is correct
15 Correct 179 ms 20684 KB Output is correct
16 Correct 171 ms 20648 KB Output is correct
17 Correct 164 ms 20632 KB Output is correct
18 Correct 160 ms 20684 KB Output is correct
19 Correct 189 ms 20612 KB Output is correct
20 Correct 90 ms 17644 KB Output is correct
21 Correct 25 ms 13716 KB Output is correct
22 Correct 126 ms 19464 KB Output is correct
23 Correct 142 ms 19724 KB Output is correct
24 Correct 134 ms 19812 KB Output is correct
25 Correct 169 ms 19516 KB Output is correct
26 Correct 130 ms 19988 KB Output is correct
27 Correct 162 ms 20512 KB Output is correct
28 Correct 196 ms 20664 KB Output is correct
29 Correct 172 ms 20504 KB Output is correct
30 Correct 91 ms 17704 KB Output is correct
31 Correct 157 ms 20796 KB Output is correct
32 Correct 127 ms 19788 KB Output is correct
33 Correct 139 ms 19984 KB Output is correct
34 Correct 114 ms 20224 KB Output is correct
35 Correct 141 ms 20292 KB Output is correct
36 Correct 147 ms 20440 KB Output is correct
37 Correct 142 ms 19956 KB Output is correct
38 Correct 151 ms 20268 KB Output is correct
39 Correct 101 ms 20720 KB Output is correct
40 Correct 148 ms 20336 KB Output is correct
41 Correct 152 ms 20252 KB Output is correct
# Verdict Execution time Memory Grader output
1 Incorrect 5 ms 10452 KB Output isn't correct
2 Halted 0 ms 0 KB -