oj.uz

Submission #755098

# Submission time Handle Problem Language Result Execution time Memory
755098 2023-06-09T11:53:10 Z boris_mihov Radio Towers (IOI22_towers) C++17
17 / 100
 1203 ms 115052 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 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;
SparseMIN 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;
    }

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

    if (L <= a[first] && a[first] < first - 1)
    {
        int res = sparseMIN.findMIN(L, a[first]);
        if (res + D <= sparseMAX.findMAX(a[first] + 1, first - 1))
        {
            cnt++;
        }
    }

    if (c[last] <= R && last + 1 < c[last])
    {
        int res = sparseMIN.findMIN(c[last], R);
        if (res + D <= sparseMAX.findMAX(last + 1, c[last] - 1))
        {
            cnt++;
            assert(false);
        }
    }

    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)
      |                       ~~~~~~^~~
towers.cpp: In member function 'void SparseMIN::build(int*)':
towers.cpp:233:97: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
  233 |                 sparseMIN[log][i] = cmp(sparseMIN[log - 1][i], sparseMIN[log - 1][i + (1 << log - 1)]);
      |                                                                                             ~~~~^~~
towers.cpp:240:29: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
  240 |             if ((1 << lg[i] + 1) < i)
      |                       ~~~~~~^~~

Subtask #1
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 457 ms 45384 KB 12th lines differ - on the 1st token, expected: '2', found: '1'
2 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 28692 KB Output is correct
2 Correct 17 ms 29008 KB Output is correct
3 Correct 16 ms 29016 KB Output is correct
4 Correct 16 ms 28932 KB Output is correct
5 Correct 17 ms 29044 KB Output is correct
6 Correct 16 ms 29008 KB Output is correct
7 Incorrect 16 ms 29008 KB 1st lines differ - on the 1st token, expected: '34', found: '33'
8 Halted 0 ms 0 KB -

Subtask #3
0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 28692 KB Output is correct
2 Correct 17 ms 29008 KB Output is correct
3 Correct 16 ms 29016 KB Output is correct
4 Correct 16 ms 28932 KB Output is correct
5 Correct 17 ms 29044 KB Output is correct
6 Correct 16 ms 29008 KB Output is correct
7 Incorrect 16 ms 29008 KB 1st lines differ - on the 1st token, expected: '34', found: '33'
8 Halted 0 ms 0 KB -

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Runtime error 105 ms 115052 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 336 ms 34968 KB Output is correct
2 Correct 1094 ms 57328 KB Output is correct
3 Correct 1136 ms 57364 KB Output is correct
4 Correct 989 ms 57336 KB Output is correct
5 Correct 1203 ms 57296 KB Output is correct
6 Correct 1036 ms 57300 KB Output is correct
7 Correct 1107 ms 57272 KB Output is correct
8 Correct 989 ms 57528 KB Output is correct
9 Correct 976 ms 57716 KB Output is correct
10 Correct 914 ms 57404 KB Output is correct
11 Correct 990 ms 57412 KB Output is correct
12 Correct 79 ms 57304 KB Output is correct
13 Correct 68 ms 57364 KB Output is correct
14 Correct 78 ms 57288 KB Output is correct
15 Correct 68 ms 57792 KB Output is correct
16 Correct 61 ms 57292 KB Output is correct
17 Correct 67 ms 56476 KB Output is correct
18 Correct 76 ms 57292 KB Output is correct
19 Correct 77 ms 57340 KB Output is correct
20 Correct 68 ms 57276 KB Output is correct
21 Correct 71 ms 57284 KB Output is correct
22 Correct 77 ms 57308 KB Output is correct
23 Correct 86 ms 57292 KB Output is correct
24 Correct 67 ms 57340 KB Output is correct
25 Correct 68 ms 57812 KB Output is correct
26 Correct 71 ms 57292 KB Output is correct
27 Correct 73 ms 57684 KB Output is correct
28 Correct 16 ms 29008 KB Output is correct
29 Correct 20 ms 29008 KB Output is correct
30 Correct 16 ms 28932 KB Output is correct
31 Correct 17 ms 29008 KB Output is correct
32 Correct 15 ms 29008 KB Output is correct
33 Correct 14 ms 28752 KB Output is correct
34 Correct 16 ms 29008 KB Output is correct
35 Correct 15 ms 28996 KB Output is correct
36 Correct 16 ms 29028 KB Output is correct
37 Correct 15 ms 28924 KB Output is correct
38 Correct 16 ms 29000 KB Output is correct
39 Correct 17 ms 29008 KB Output is correct
40 Correct 20 ms 29008 KB Output is correct
41 Correct 15 ms 29008 KB Output is correct
42 Correct 16 ms 29008 KB Output is correct
43 Correct 15 ms 29008 KB Output is correct

Subtask #6
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 16 ms 28692 KB Output is correct
2 Correct 17 ms 29008 KB Output is correct
3 Correct 16 ms 29016 KB Output is correct
4 Correct 16 ms 28932 KB Output is correct
5 Correct 17 ms 29044 KB Output is correct
6 Correct 16 ms 29008 KB Output is correct
7 Incorrect 16 ms 29008 KB 1st lines differ - on the 1st token, expected: '34', found: '33'
8 Halted 0 ms 0 KB -

Subtask #7
0 / 23.0

# Verdict Execution time Memory Grader output
1 Incorrect 457 ms 45384 KB 12th lines differ - on the 1st token, expected: '2', found: '1'
2 Halted 0 ms 0 KB -