oj.uz

Submission #771778

# Submission time Handle Problem Language Result Execution time Memory
771778 2023-07-03T09:15:38 Z drdilyor Radio Towers (IOI22_towers) C++17
17 / 100
 1705 ms 32296 KB 
#include <bits/stdc++.h>
#include "towers.h"
using namespace std;
using ll = long long;
constexpr int inf = 1e9;

template<typename T, typename Op>
struct SparseTable {
    vector<vector<T>> sparse;
    Op accum_func;

    SparseTable() = default;

    SparseTable(const vector<T>& arr, const Op func) : accum_func(func) {
        int n = arr.size();
        int logn = 32 - __builtin_clz(n);
        sparse.resize(logn, vector<T>(n));
        sparse[0] = arr;
        for (int lg = 1; lg < logn; lg++) {
            for (int i = 0; i + (1 << lg) <= n; i++) {
                sparse[lg][i] = accum_func(sparse[lg - 1][i], sparse[lg - 1][i + (1 << (lg - 1))]);
            }
        }
    }

    T find(int l, int r) { // [l, r]
        r++;
        int cur_log = 31 - __builtin_clz(r - l);
        return accum_func(sparse[cur_log][l], sparse[cur_log][r - (1 << cur_log)]);
    }
};

struct SegmentTree {
    using T = vector<int>;
    using S = int;
    const T id = {};
    inline T single(S v) { return {v}; }

    T merge(const T& l, const T& r) {
        T res(l.size() + r.size());
        std::merge(l.cbegin(), l.cend(),
              r.cbegin(), r.cend(),
              res.begin());
        return res;
    }

    int n;
    vector<T> tree;

    SegmentTree() = default;
    void init(vector<S> arr) {
        n = arr.size();
        tree.resize(n * 2, id);
        for (int i = 0; i < n; i++) {
            tree[i + n] = single(arr[i]);
        }
        build();
    }

    void build() {
        for (int i = n-1; i >= 1; i--) {
            tree[i] = merge(tree[i*2], tree[i*2 + 1]);
        }
    }

    void update(int i, S v) {
        tree[i+=n] = single(v);
        for (i /= 2; i >= 1; i/= 2)
            tree[i] = merge(tree[i*2], tree[i*2+1]);
    }

    tuple<int,int,int> query(int l, int r, int x) {
        int cnt = 0;
        int left = -1, right = -1;
        l += n; r += n;
        while (l <= r) {
            if (l % 2 == 1) {
                if (left ==-1) left = leftmost(l, x);
                cnt += count_ge(tree[l++], x);
            }
            if (r % 2 == 0) {
                if (right == -1) right = rightmost(r, x);
                cnt += count_ge(tree[r--], x);
            }
            l /= 2; r /= 2;
        }
        return {cnt, left, right};
    }

    int count_ge(T& v, int x) {
        return v.end() - lower_bound(v.begin(), v.end(), x);
    }

    int leftmost(int v, int x, bool rev=0) {
        if (tree[v].back() < x) return -1;
        while (v < n) {
            if (tree[v*2+rev].back() >= x) v = v * 2 +rev;
            else v = v * 2 + 1 -rev;
        }
        return v - n;
    }
    int rightmost(int v, int x) {
        return leftmost(v, x, 1);
    }
};


int st_min(int a, int b) { return min(a, b); }
int st_max(int a, int b) { return max(a, b); }

int n;
vector<int> h, ix;
SparseTable<int, decltype(&st_min)> hmax;
SparseTable<int, decltype(&st_max)> hmin;

vector<int> start;
SegmentTree ans;

int find_left(int i, int d) {
    int l = -1, r = i;
    while (l < r-1) {
        int mid = (l+r) / 2;
        if (hmax.find(mid, i) - h[i] >= d)
            l = mid;
        else r = mid;
    }
    return l;
}

int find_right(int i, int d) {
    int l = i, r = n;
    while (l < r-1) {
        int mid = (l+r) / 2;
        if (hmax.find(i, mid) - h[i] >= d)
            r = mid;
        else l = mid;
    }
    return r;
}

void init(int N, std::vector<int> H) {
    n = N, h = H;
    ix.resize(n);
    start.resize(n);
    iota(ix.begin(), ix.end(), 0);
    sort(ix.begin(), ix.end(), [&](int i, int j) {
            return h[i] < h[j];
            });
    hmax = SparseTable(h, st_max);
    hmin = SparseTable(h, st_min);
    const int L = 0, R = n-1;

    for (int i = 0; i < n;i++) {
        int lD = 0, rD = inf+1;
        while (lD < rD-1) {
            int D = (lD + rD) / 2;
            bool ok = 1;

            int lg = find_left(i, D);
            if (hmin.find(lg+1, i) < h[i]) ok = 0;

            int rg = find_right(i, D);
            if (hmin.find(i, rg-1) < h[i]) ok = 0;

            if (ok) lD = D;
            else rD = D;
        }
        start[i] = lD;
    }
    ans.init(start);
}

int max_towers(int L, int R, int D) {
    auto [cnt, left, right] = ans.query(L, R, D);

    return cnt;
}

Compilation message

towers.cpp: In function 'void init(int, std::vector<int>)':
towers.cpp:151:15: warning: unused variable 'L' [-Wunused-variable]
  151 |     const int L = 0, R = n-1;
      |               ^
towers.cpp:151:22: warning: unused variable 'R' [-Wunused-variable]
  151 |     const int L = 0, R = n-1;
      |                      ^

Subtask #1
0 / 4.0

# Verdict Execution time Memory Grader output
1 Incorrect 841 ms 18696 KB 1st lines differ - on the 1st token, expected: '1', found: '0'
2 Halted 0 ms 0 KB -

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 12 ms 764 KB Output is correct
3 Correct 11 ms 768 KB Output is correct
4 Correct 11 ms 720 KB Output is correct
5 Correct 11 ms 768 KB Output is correct
6 Correct 12 ms 768 KB Output is correct
7 Incorrect 11 ms 768 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 3 ms 332 KB Output is correct
2 Correct 12 ms 764 KB Output is correct
3 Correct 11 ms 768 KB Output is correct
4 Correct 11 ms 720 KB Output is correct
5 Correct 11 ms 768 KB Output is correct
6 Correct 12 ms 768 KB Output is correct
7 Incorrect 11 ms 768 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 Incorrect 1427 ms 31960 KB 1st lines differ - on the 1st token, expected: '11903', found: '11902'
2 Halted 0 ms 0 KB -

Subtask #5
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 442 ms 7352 KB Output is correct
2 Correct 1646 ms 32224 KB Output is correct
3 Correct 1705 ms 32228 KB Output is correct
4 Correct 1438 ms 32244 KB Output is correct
5 Correct 1394 ms 32224 KB Output is correct
6 Correct 1593 ms 32232 KB Output is correct
7 Correct 1620 ms 32224 KB Output is correct
8 Correct 1355 ms 32276 KB Output is correct
9 Correct 1408 ms 32232 KB Output is correct
10 Correct 1602 ms 32224 KB Output is correct
11 Correct 1597 ms 32224 KB Output is correct
12 Correct 813 ms 32224 KB Output is correct
13 Correct 827 ms 32220 KB Output is correct
14 Correct 815 ms 32228 KB Output is correct
15 Correct 795 ms 32236 KB Output is correct
16 Correct 759 ms 32244 KB Output is correct
17 Correct 799 ms 31212 KB Output is correct
18 Correct 807 ms 32224 KB Output is correct
19 Correct 816 ms 32236 KB Output is correct
20 Correct 806 ms 32224 KB Output is correct
21 Correct 839 ms 32228 KB Output is correct
22 Correct 813 ms 32236 KB Output is correct
23 Correct 813 ms 32220 KB Output is correct
24 Correct 753 ms 32276 KB Output is correct
25 Correct 768 ms 32296 KB Output is correct
26 Correct 776 ms 32232 KB Output is correct
27 Correct 769 ms 32236 KB Output is correct
28 Correct 11 ms 720 KB Output is correct
29 Correct 10 ms 720 KB Output is correct
30 Correct 10 ms 720 KB Output is correct
31 Correct 11 ms 772 KB Output is correct
32 Correct 10 ms 764 KB Output is correct
33 Correct 4 ms 464 KB Output is correct
34 Correct 10 ms 768 KB Output is correct
35 Correct 10 ms 720 KB Output is correct
36 Correct 10 ms 768 KB Output is correct
37 Correct 10 ms 768 KB Output is correct
38 Correct 11 ms 764 KB Output is correct
39 Correct 10 ms 768 KB Output is correct
40 Correct 9 ms 720 KB Output is correct
41 Correct 10 ms 772 KB Output is correct
42 Correct 9 ms 720 KB Output is correct
43 Correct 10 ms 768 KB Output is correct

Subtask #6
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 332 KB Output is correct
2 Correct 12 ms 764 KB Output is correct
3 Correct 11 ms 768 KB Output is correct
4 Correct 11 ms 720 KB Output is correct
5 Correct 11 ms 768 KB Output is correct
6 Correct 12 ms 768 KB Output is correct
7 Incorrect 11 ms 768 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 841 ms 18696 KB 1st lines differ - on the 1st token, expected: '1', found: '0'
2 Halted 0 ms 0 KB -