oj.uz

Submission #755138

# Submission time Handle Problem Language Result Execution time Memory
755138 2023-06-09T12:38:49 Z boris_mihov Radio Towers (IOI22_towers) C++17
17 / 100
 1320 ms 57164 KB 
#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <vector>
#include <stack>

typedef long long llong;
const int MAXLOG = 20 + 5;
const int MAXN = 100000 + 10;
const int INF  = 1e9;

int n;
struct MST
{
    std::vector <int> tree[4*MAXN];
    void build(int l, int r, int node, int vals[])
    {
        if (l == r)
        {
            tree[node].push_back(vals[l]);
            return;
        }

        int mid = (l + r) / 2;
        build(l, mid, 2*node, vals);
        build(mid + 1, r, 2*node + 1, vals);
        tree[node].reserve(r - l + 1);

        int lPtr = 0, rPtr = 0;
        for (int i = l ; i <= r ; ++i)
        {
            if (lPtr == tree[2*node].size())
            {
                tree[node].push_back(tree[2*node + 1][rPtr++]);
                continue;
            }

            if (rPtr == tree[2*node + 1].size())
            {
                tree[node].push_back(tree[2*node][lPtr++]);
                continue;
            }

            if (tree[2*node][lPtr] < tree[2*node + 1][rPtr])
            {
                tree[node].push_back(tree[2*node][lPtr++]);
            } else
            {
                tree[node].push_back(tree[2*node + 1][rPtr++]);
            }
        }
    }

    int binaryCount(int node, int val)
    {
        int l = -1, r = tree[node].size(), mid;
        while (l < r - 1)
        {
            mid = (l + r) / 2;
            if (tree[node][mid] <= val) l = mid;
            else r = mid;
        }

        return r;
    }

    int binaryFirst(int node, int val)
    {
        int l = -1, r = tree[node].size(), mid;
        while (l < r - 1)
        {
            mid = (l + r) / 2;
            if (tree[node][mid] < val) l = mid;
            else r = mid;
        }

        return (r == tree[node].size() ? INF : tree[node][r]);
    }

    int binaryLast(int node, int val)
    {
        int l = -1, r = tree[node].size(), mid;
        while (l < r - 1)
        {
            mid = (l + r) / 2;
            if (tree[node][mid] <= val) l = mid;
            else r = mid;
        }

        return (l == -1 ? 0 : tree[node][l]);
    }

    int queryCount(int l, int r, int node, int queryL, int queryR, int queryValL, int queryValR)
    {
        if (queryL <= l && r <= queryR)
        {
            return binaryCount(node, queryValR) - binaryCount(node, queryValL - 1);
        }

        int res = 0;
        int mid = (l + r) / 2;
        if (queryL <= mid) res += queryCount(l, mid, 2*node, queryL, queryR, queryValL, queryValR);
        if (mid + 1 <= queryR) res += queryCount(mid + 1, r, 2*node + 1, queryL, queryR, queryValL, queryValR);
        return res;
    }

    int queryFirst(int l, int r, int node, int queryL, int queryR, int queryVal)
    {
        if (queryL <= l && r <= queryR)
        {
            return binaryFirst(node, queryVal);
        }

        int res = INF;
        int mid = (l + r) / 2;
        if (queryL <= mid) res = std::min(res, queryFirst(l, mid, 2*node, queryL, queryR, queryVal));
        if (mid + 1 <= queryR) res = std::min(res, queryFirst(mid + 1, r, 2*node + 1, queryL, queryR, queryVal));
        return res;
    }

    int queryLast(int l, int r, int node, int queryL, int queryR, int queryVal)
    {
        if (queryL <= l && r <= queryR)
        {
            return binaryLast(node, queryVal);
        }

        int res = 0;
        int mid = (l + r) / 2;
        if (queryL <= mid) res = std::max(res, queryLast(l, mid, 2*node, queryL, queryR, queryVal));
        if (mid + 1 <= queryR) res = std::max(res, queryLast(mid + 1, r, 2*node + 1, queryL, queryR, queryVal));
        return res;
    }

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

    int queryCount(int to, int l, int r)
    {
        return queryCount(1, n, 1, 1, to, l, r);
    }

    int queryFirst(int to, int l)
    {
        return queryFirst(1, n, 1, 1, to, l);
    }

    int queryLast(int to, int r)
    {
        return queryLast(1, n, 1, 1, to, r);
    }
};

MST left, right;
struct SparseMAX
{
    int sparseMAX[MAXLOG][MAXN];
    int vals[MAXN];
    int lg[MAXN];

    int cmp(int x, int y)
    {
        if (vals[x] > vals[y]) return x;
        return y;
    }

    void build(int _vals[])
    {
        for (int i = 1 ; i <= n ; ++i)
        {
            sparseMAX[0][i] = i;
            vals[i] = _vals[i];
        }

        for (int log = 1 ; (1 << log) <= n ; ++log)
        {
            for (int i = 1 ; i + (1 << log) - 1 <= n ; ++i)
            {
                sparseMAX[log][i] = cmp(sparseMAX[log - 1][i], sparseMAX[log - 1][i + (1 << log - 1)]);
            }
        }
    
        for (int i = 1 ; i <= n ; ++i)
        {
            lg[i] = lg[i - 1];
            if ((1 << lg[i] + 1) < i)
            {
                lg[i]++;
            }
        }
    }

    int findMAX(int l, int r)
    {
        int log = lg[r - l + 1];
        return vals[cmp(sparseMAX[log][l], sparseMAX[log][r - (1 << log) + 1])];
    }

    int findIDX(int l, int r)
    {
        int log = lg[r - l + 1];
        return cmp(sparseMAX[log][l], sparseMAX[log][r - (1 << log) + 1]);
    }
};

struct SegmentTree
{
    struct Node
    {
        int max;
        int min;
        int maxDiffL;
        int maxDiffR;
        
        Node()
        {
            max = -1;
        }
    };

    Node combine(Node left, Node right)
    {
        if (left.max == -1)
        {
            return right;
        }

        Node res;
        res.min = std::min(left.min, right.min);
        res.max = std::max(left.max, right.max);
        res.maxDiffL = std::max(left.maxDiffL, right.maxDiffL);
        res.maxDiffR = std::max(left.maxDiffR, right.maxDiffR);
        res.maxDiffL = std::max(res.maxDiffL, right.max - left.min);
        res.maxDiffR = std::max(res.maxDiffR, left.max - right.min);
        return res;
    }

    Node tree[4*MAXN];
    void build(int l, int r, int node, int vals[])
    {
        if (l == r)
        {
            tree[node].min = vals[l];
            tree[node].max = vals[l];
            tree[node].maxDiffL = 0;
            tree[node].maxDiffR = 0;
            return;
        }

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

    Node query(int l, int r, int node, int queryL, int queryR)
    {
        if (queryL <= l && r <= queryR)
        {
            return tree[node];
        }

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

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

    int queryL(int l, int r)
    {
        return query(1, n, 1, l, r).maxDiffL;
    }

    int queryR(int l, int r)
    {
        return query(1, n, 1, l, r).maxDiffR;
    }
};

int a[MAXN];
int b[MAXN];
int c[MAXN];
int d[MAXN];
int h[MAXN];
int perm[MAXN];
int cost[MAXN];
SparseMAX sparseMAX;
SegmentTree maxDiff;
std::stack <int> st;
std::vector <int> v;
MST tree;

void init(int N, std::vector <int> H) 
{
    n = N;
    for (int i = 1 ; i <= n ; ++i)
    {
        h[i] = H[i - 1];
    }

    sparseMAX.build(h);
    st.push(0);

    for (int i = 1 ; i <= n ; ++i)
    {
        while (h[st.top()] > h[i])
        {
            st.pop();
        }

        a[i] = st.top();
        st.push(i);
    }


    while (!st.empty())
    {
        st.pop();
    }

    st.push(n + 1);
    for (int i = n ; i >= 1 ; --i)
    {
        while (h[st.top()] > h[i])
        {
            st.pop();
        }

        c[i] = st.top();
        st.push(i);
    }

    for (int i = 1 ; i <= n ; ++i)
    {
        if (a[i] == i - 1)
        {
            b[i] = 0;
        } else
        {
            b[i] = sparseMAX.findMAX(a[i] + 1, i - 1) - h[i];
        }

        if (c[i] == i + 1)
        {
            d[i] = 0;
        } else
        {
            d[i] = sparseMAX.findMAX(i + 1, c[i] - 1) - h[i];
        }
    }

    for (int i = 1 ; i <= n ; ++i)
    {
        cost[i] = INF; 
        if (a[i] > 0) cost[i] = std::min(cost[i], b[i]);
        if (c[i] < n + 1) cost[i] = std::min(cost[i], d[i]);
    }

    std::iota(perm + 1, perm + 1 + n, 1);
    std::sort(perm + 1, perm + 1 + n, [&](const int &x, const int &y)
    {
        return cost[x] > cost[y];
    });

    tree.build(perm);
    maxDiff.build(h);
}

int max_towers(int L, int R, int D) 
{
    L++; R++;
    int l = 0, r = n + 1, mid;
    while (l < r - 1)
    {
        mid = (l + r) / 2;
        if (cost[perm[mid]] >= D) l = mid;
        else r = mid;
    }

    if (l == 0)
    {
        return 1;
    }

    int cnt = tree.queryCount(l, L, R);
    if (cnt == 0)
    {
        return 2;
    }

    int first = tree.queryFirst(l, L);
    int last = tree.queryLast(l, R);

    l = L, r = first;
    while (l < r - 1)
    {
        mid = (l + r) / 2;
        if (sparseMAX.findMAX(mid, first - 1) < h[first] + D) r = mid;
        else l = mid;
    }

    if (maxDiff.queryL(L, l) >= D)
    {
        cnt++;
    }

    l = last, r = R;
    while (l < r - 1)
    {
        mid = (l + r) / 2;
        if (sparseMAX.findMAX(last + 1, mid) < h[last] + D) l = mid;
        else r = mid;
    }

    if (maxDiff.queryR(r, R) >= D)
    {
        cnt++;
    }

    return cnt;
}

Compilation message

towers.cpp: In member function 'void MST::build(int, int, int, int*)':
towers.cpp:33:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |             if (lPtr == tree[2*node].size())
      |                 ~~~~~^~~~~~~~~~~~~~~~~~~~~~
towers.cpp:39:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |             if (rPtr == tree[2*node + 1].size())
      |                 ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
towers.cpp: In member function 'int MST::binaryFirst(int, int)':
towers.cpp:78:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   78 |         return (r == tree[node].size() ? INF : tree[node][r]);
      |                 ~~^~~~~~~~~~~~~~~~~~~~
towers.cpp: In member function 'void SparseMAX::build(int*)':
towers.cpp:182:97: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  182 |                 sparseMAX[log][i] = cmp(sparseMAX[log - 1][i], sparseMAX[log - 1][i + (1 << log - 1)]);
      |                                                                                             ~~~~^~~
towers.cpp:189:29: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
  189 |             if ((1 << lg[i] + 1) < i)
      |                       ~~~~~~^~~

Subtask #1
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 606 ms 47612 KB 1st lines differ - on the 1st token, expected: '1', found: '2'
2 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 34872 KB Output is correct
2 Correct 20 ms 35132 KB Output is correct
3 Correct 20 ms 35120 KB Output is correct
4 Correct 19 ms 35092 KB Output is correct
5 Correct 18 ms 35152 KB Output is correct
6 Correct 21 ms 35160 KB Output is correct
7 Correct 19 ms 35152 KB Output is correct
8 Incorrect 23 ms 35152 KB 1st lines differ - on the 1st token, expected: '1', found: '2'
9 Halted 0 ms 0 KB -

Subtask #3
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 34872 KB Output is correct
2 Correct 20 ms 35132 KB Output is correct
3 Correct 20 ms 35120 KB Output is correct
4 Correct 19 ms 35092 KB Output is correct
5 Correct 18 ms 35152 KB Output is correct
6 Correct 21 ms 35160 KB Output is correct
7 Correct 19 ms 35152 KB Output is correct
8 Incorrect 23 ms 35152 KB 1st lines differ - on the 1st token, expected: '1', found: '2'
9 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Incorrect 964 ms 56508 KB 74909th lines differ - on the 1st token, expected: '1', found: '2'
2 Halted 0 ms 0 KB -

Subtask #5
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 352 ms 39704 KB Output is correct
2 Correct 1092 ms 56672 KB Output is correct
3 Correct 1101 ms 56652 KB Output is correct
4 Correct 1189 ms 56632 KB Output is correct
5 Correct 1320 ms 56624 KB Output is correct
6 Correct 1044 ms 56632 KB Output is correct
7 Correct 1316 ms 56688 KB Output is correct
8 Correct 1111 ms 56644 KB Output is correct
9 Correct 1102 ms 57164 KB Output is correct
10 Correct 1018 ms 56616 KB Output is correct
11 Correct 801 ms 56788 KB Output is correct
12 Correct 75 ms 56708 KB Output is correct
13 Correct 86 ms 56668 KB Output is correct
14 Correct 77 ms 56696 KB Output is correct
15 Correct 68 ms 57032 KB Output is correct
16 Correct 68 ms 56624 KB Output is correct
17 Correct 72 ms 56008 KB Output is correct
18 Correct 68 ms 56636 KB Output is correct
19 Correct 80 ms 56656 KB Output is correct
20 Correct 71 ms 56684 KB Output is correct
21 Correct 71 ms 56740 KB Output is correct
22 Correct 78 ms 56616 KB Output is correct
23 Correct 84 ms 56628 KB Output is correct
24 Correct 66 ms 56704 KB Output is correct
25 Correct 63 ms 57016 KB Output is correct
26 Correct 65 ms 56648 KB Output is correct
27 Correct 71 ms 57020 KB Output is correct
28 Correct 20 ms 35136 KB Output is correct
29 Correct 19 ms 35160 KB Output is correct
30 Correct 21 ms 35136 KB Output is correct
31 Correct 19 ms 35108 KB Output is correct
32 Correct 19 ms 35152 KB Output is correct
33 Correct 19 ms 34896 KB Output is correct
34 Correct 20 ms 35152 KB Output is correct
35 Correct 22 ms 35092 KB Output is correct
36 Correct 23 ms 35156 KB Output is correct
37 Correct 20 ms 35080 KB Output is correct
38 Correct 20 ms 35152 KB Output is correct
39 Correct 19 ms 35152 KB Output is correct
40 Correct 20 ms 35168 KB Output is correct
41 Correct 20 ms 35152 KB Output is correct
42 Correct 25 ms 35140 KB Output is correct
43 Correct 19 ms 35152 KB Output is correct

Subtask #6
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 18 ms 34872 KB Output is correct
2 Correct 20 ms 35132 KB Output is correct
3 Correct 20 ms 35120 KB Output is correct
4 Correct 19 ms 35092 KB Output is correct
5 Correct 18 ms 35152 KB Output is correct
6 Correct 21 ms 35160 KB Output is correct
7 Correct 19 ms 35152 KB Output is correct
8 Incorrect 23 ms 35152 KB 1st lines differ - on the 1st token, expected: '1', found: '2'
9 Halted 0 ms 0 KB -

Subtask #7
0 / 23.0

# Verdict Execution time Memory Grader output
1 Incorrect 606 ms 47612 KB 1st lines differ - on the 1st token, expected: '1', found: '2'
2 Halted 0 ms 0 KB -