Submission #755085

# Submission time Handle Problem Language Result Execution time Memory
755085 2023-06-09T11:36:34 Z boris_mihov Radio Towers (IOI22_towers) C++17
17 / 100
1411 ms 57796 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 = 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 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)
      |                       ~~~~~~^~~
# Verdict Execution time Memory Grader output
1 Incorrect 435 ms 45320 KB 12th lines differ - on the 1st token, expected: '2', found: '1'
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 18 ms 28648 KB Output is correct
2 Correct 19 ms 28952 KB Output is correct
3 Correct 20 ms 28968 KB Output is correct
4 Correct 23 ms 29008 KB Output is correct
5 Correct 22 ms 29008 KB Output is correct
6 Correct 22 ms 29028 KB Output is correct
7 Incorrect 19 ms 28988 KB 1st lines differ - on the 1st token, expected: '34', found: '33'
8 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 18 ms 28648 KB Output is correct
2 Correct 19 ms 28952 KB Output is correct
3 Correct 20 ms 28968 KB Output is correct
4 Correct 23 ms 29008 KB Output is correct
5 Correct 22 ms 29008 KB Output is correct
6 Correct 22 ms 29028 KB Output is correct
7 Incorrect 19 ms 28988 KB 1st lines differ - on the 1st token, expected: '34', found: '33'
8 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 1028 ms 57192 KB 1st lines differ - on the 1st token, expected: '11903', found: '11902'
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 294 ms 34972 KB Output is correct
2 Correct 1386 ms 57376 KB Output is correct
3 Correct 1149 ms 57300 KB Output is correct
4 Correct 1411 ms 57364 KB Output is correct
5 Correct 1380 ms 57304 KB Output is correct
6 Correct 1269 ms 57272 KB Output is correct
7 Correct 1207 ms 57316 KB Output is correct
8 Correct 747 ms 57336 KB Output is correct
9 Correct 973 ms 57784 KB Output is correct
10 Correct 800 ms 57396 KB Output is correct
11 Correct 852 ms 57428 KB Output is correct
12 Correct 73 ms 57356 KB Output is correct
13 Correct 72 ms 57336 KB Output is correct
14 Correct 71 ms 57284 KB Output is correct
15 Correct 72 ms 57796 KB Output is correct
16 Correct 66 ms 57408 KB Output is correct
17 Correct 74 ms 56492 KB Output is correct
18 Correct 81 ms 57284 KB Output is correct
19 Correct 73 ms 57336 KB Output is correct
20 Correct 72 ms 57292 KB Output is correct
21 Correct 77 ms 57280 KB Output is correct
22 Correct 80 ms 57360 KB Output is correct
23 Correct 74 ms 57324 KB Output is correct
24 Correct 68 ms 57416 KB Output is correct
25 Correct 68 ms 57724 KB Output is correct
26 Correct 67 ms 57408 KB Output is correct
27 Correct 70 ms 57672 KB Output is correct
28 Correct 16 ms 29008 KB Output is correct
29 Correct 17 ms 29008 KB Output is correct
30 Correct 17 ms 29000 KB Output is correct
31 Correct 17 ms 28944 KB Output is correct
32 Correct 17 ms 28956 KB Output is correct
33 Correct 18 ms 28752 KB Output is correct
34 Correct 16 ms 29008 KB Output is correct
35 Correct 17 ms 29024 KB Output is correct
36 Correct 16 ms 29008 KB Output is correct
37 Correct 16 ms 28988 KB Output is correct
38 Correct 16 ms 28932 KB Output is correct
39 Correct 17 ms 29008 KB Output is correct
40 Correct 17 ms 28968 KB Output is correct
41 Correct 18 ms 29004 KB Output is correct
42 Correct 17 ms 29008 KB Output is correct
43 Correct 18 ms 28988 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 18 ms 28648 KB Output is correct
2 Correct 19 ms 28952 KB Output is correct
3 Correct 20 ms 28968 KB Output is correct
4 Correct 23 ms 29008 KB Output is correct
5 Correct 22 ms 29008 KB Output is correct
6 Correct 22 ms 29028 KB Output is correct
7 Incorrect 19 ms 28988 KB 1st lines differ - on the 1st token, expected: '34', found: '33'
8 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Incorrect 435 ms 45320 KB 12th lines differ - on the 1st token, expected: '2', found: '1'
2 Halted 0 ms 0 KB -