oj.uz

Submission #755081

# Submission time Handle Problem Language Result Execution time Memory
755081 2023-06-09T11:35:19 Z boris_mihov Radio Towers (IOI22_towers) C++17
17 / 100
 1177 ms 115080 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)
        {
            assert(binaryCount(node, queryValL - 1) == 0);
            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 = INF;
        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 queryFirst(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 SparseMIN
{
    int SparseMIN[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)
        {
            SparseMIN[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)
            {
                SparseMIN[log][i] = cmp(SparseMIN[log - 1][i], SparseMIN[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 findMIN(int l, int r)
    {
        int log = lg[r - l + 1];
        return vals[cmp(SparseMIN[log][l], SparseMIN[log][r - (1 << log) + 1])];
    }

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

int a[MAXN];
int b[MAXN];
int c[MAXN];
int d[MAXN];
int h[MAXN];
int perm[MAXN];
int cost[MAXN];
SparseMAX sparseMAX;
SparseMAX sparseMIN;
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];
    }

    sparseMIN.build(h);
    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);
}

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 1;
    }

    return l;
}

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:183:97: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  183 |                 sparseMAX[log][i] = cmp(sparseMAX[log - 1][i], sparseMAX[log - 1][i + (1 << log - 1)]);
      |                                                                                             ~~~~^~~
towers.cpp:190:29: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
  190 |             if ((1 << lg[i] + 1) < i)
      |                       ~~~~~~^~~
towers.cpp: In member function 'void SparseMIN::build(int*)':
towers.cpp:234:97: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  234 |                 SparseMIN[log][i] = cmp(SparseMIN[log - 1][i], SparseMIN[log - 1][i + (1 << log - 1)]);
      |                                                                                             ~~~~^~~
towers.cpp:241:29: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
  241 |             if ((1 << lg[i] + 1) < i)
      |                       ~~~~~~^~~

Subtask #1
0 / 4.0

# Verdict Execution time Memory Grader output
1 Runtime error 80 ms 91360 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Runtime error 40 ms 57888 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #3
0 / 12.0

# Verdict Execution time Memory Grader output
1 Runtime error 40 ms 57888 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Runtime error 106 ms 115080 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #5
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 326 ms 35088 KB Output is correct
2 Correct 1113 ms 57304 KB Output is correct
3 Correct 1177 ms 57288 KB Output is correct
4 Correct 989 ms 57288 KB Output is correct
5 Correct 971 ms 57360 KB Output is correct
6 Correct 1175 ms 57344 KB Output is correct
7 Correct 1012 ms 57444 KB Output is correct
8 Correct 974 ms 57332 KB Output is correct
9 Correct 830 ms 57784 KB Output is correct
10 Correct 989 ms 57416 KB Output is correct
11 Correct 942 ms 57468 KB Output is correct
12 Correct 70 ms 57372 KB Output is correct
13 Correct 69 ms 57316 KB Output is correct
14 Correct 72 ms 57340 KB Output is correct
15 Correct 62 ms 57708 KB Output is correct
16 Correct 61 ms 57412 KB Output is correct
17 Correct 68 ms 56484 KB Output is correct
18 Correct 68 ms 57388 KB Output is correct
19 Correct 71 ms 57392 KB Output is correct
20 Correct 69 ms 57300 KB Output is correct
21 Correct 70 ms 57288 KB Output is correct
22 Correct 72 ms 57300 KB Output is correct
23 Correct 69 ms 57384 KB Output is correct
24 Correct 63 ms 57412 KB Output is correct
25 Correct 65 ms 57740 KB Output is correct
26 Correct 63 ms 57400 KB Output is correct
27 Correct 63 ms 57788 KB Output is correct
28 Correct 16 ms 28980 KB Output is correct
29 Correct 18 ms 28920 KB Output is correct
30 Correct 17 ms 29008 KB Output is correct
31 Correct 16 ms 29008 KB Output is correct
32 Correct 16 ms 29136 KB Output is correct
33 Correct 16 ms 28672 KB Output is correct
34 Correct 16 ms 29008 KB Output is correct
35 Correct 17 ms 29008 KB Output is correct
36 Correct 16 ms 28984 KB Output is correct
37 Correct 16 ms 29008 KB Output is correct
38 Correct 16 ms 29004 KB Output is correct
39 Correct 16 ms 29008 KB Output is correct
40 Correct 16 ms 29008 KB Output is correct
41 Correct 17 ms 29052 KB Output is correct
42 Correct 16 ms 29008 KB Output is correct
43 Correct 16 ms 28948 KB Output is correct

Subtask #6
0 / 19.0

# Verdict Execution time Memory Grader output
1 Runtime error 40 ms 57888 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -

Subtask #7
0 / 23.0

# Verdict Execution time Memory Grader output
1 Runtime error 80 ms 91360 KB Execution killed with signal 6
2 Halted 0 ms 0 KB -