oj.uz

Submission #809137

# Submission time Handle Problem Language Result Execution time Memory
809137 2023-08-05T18:35:11 Z PanosPask Dancing Elephants (IOI11_elephants) C++14
97 / 100
 9000 ms 6168 KB 
    #include "elephants.h"
    #include <bits/stdc++.h>
    #define f first
    #define s second
    #define mp make_pair
     
    using namespace std;
     
    typedef pair<int, int> pi;
     
    struct Block {
      vector<int> positions;
     
      // photos[i]: Photos required and maximum position if the first elephant to be photographed is i
      vector<pi> photos;
     
        int size(void) {
            return positions.size();
        }
    };
     
    int N, L;
    int upd = 0;
    int ttl_blocks;
    int BLOCK_SIZE;
    vector<int> loc;
    vector<Block> blocks;
     
    bool onlyfirst(const pi& a, const pi& b)
    {
        return a.f < b.f;
    }
     
    void create_photos(Block& b)
    {
        int sz = b.positions.size();
        b.photos.resize(sz);
     
        int r = sz;
        for (int i = sz - 1; i >= 0; i--) {
            while (r > i + 1 && b.positions[r - 1] > b.positions[i] + L)
                r--;
     
            if (r == sz) {
                b.photos[i] = mp(b.positions[i] + L + 1, 1);
            }
            else {
                b.photos[i] = b.photos[r];
                b.photos[i].s++;
            }
        }
    }
     
    // Merge blocks b and b + 1
    void merge_blocks(int b)
    {
        for (int i = 0; i < blocks[b + 1].size(); i++)
            blocks[b].positions.push_back(blocks[b + 1].positions[i]);
     
        blocks.erase(blocks.begin() + b + 1);
     
        create_photos(blocks[b]);
    }
     
    // Split block b
    void split_block(int b)
    {
        int mid = blocks[b].size() / 2;
     
        Block b1, b2;
        for (int i = 0; i < mid; i++)
            b1.positions.push_back(blocks[b].positions[i]);
        for (int i = mid; i < blocks[b].size(); i++)
            b2.positions.push_back(blocks[b].positions[i]);
     
        blocks.erase(blocks.begin() + b);
        blocks.insert(blocks.begin() + b, b2);
        blocks.insert(blocks.begin() + b, b1);
     
        create_photos(blocks[b]);
        create_photos(blocks[b + 1]);
    }
     
    void init(int n, int l, int X[])
    {
        N = n;
        L = l;
        BLOCK_SIZE = 500;
     
        loc.resize(N);
     
        blocks.resize(1);
        for (int i = 0; i < N; i++) {
     
            blocks[i / BLOCK_SIZE].positions.push_back(X[i]);
            loc[i] = X[i];
     
            if (i + 1 == N || (i + 1) % BLOCK_SIZE == 0) {
                create_photos(blocks[i / BLOCK_SIZE]);
                if (i + 1 != N) {
                    blocks.push_back({vector<int>(), vector<pi>()});
                }
            }
        }
    }
     
    void insert_at(int i, int v)
    {
        int pos = lower_bound(blocks[i].positions.begin(), blocks[i].positions.end(), v) - blocks[i].positions.begin();
     
        blocks[i].positions.insert(blocks[i].positions.begin() + pos, v);
     
        // if (blocks[i].size() >= BLOCK_SIZE) {
        //     split_block(i);
        // }
        // else {
            create_photos(blocks[i]);
        // }
    }
     
    void remove_from(int i, int v)
    {
        int pos = lower_bound(blocks[i].positions.begin(), blocks[i].positions.end(), v) - blocks[i].positions.begin();
     
        blocks[i].positions.erase(blocks[i].positions.begin() + pos);
     
        if (blocks[i].size() == 0) {
            blocks.erase(blocks.begin() + i);
        }
        // else if (i != blocks.size() - 1 && blocks[i].size() + blocks[i + 1].size() <= BLOCK_SIZE) {
        //     merge_blocks(i);
        // }
        // else if (i && blocks[i - 1].size() + blocks[i].size() <= BLOCK_SIZE) {
        //     merge_blocks(i - 1);
        // }
        else {
            create_photos(blocks[i]);
        }
    }
     
    pi calculate_block(int i, int pos)
    {
        Block b = blocks[i];
        if (b.positions.back() < pos)
            return mp(pos, 0);
     
        int at = lower_bound(b.positions.begin(), b.positions.end(), pos) - b.positions.begin();
     
        return b.photos[at];
    }
     
    int update(int pos, int y)
    {
        // After some updates, rebuild
        upd++;
        if (upd == 400) {
            blocks.clear();
            vector<int> p = loc;
            sort(p.begin(), p.end());
            blocks.resize(1);
            for (int i = 0; i < N; i++) {
     
                blocks[i / BLOCK_SIZE].positions.push_back(p[i]);
     
                if (i + 1 == N || (i + 1) % BLOCK_SIZE == 0) {
                    create_photos(blocks[i / BLOCK_SIZE]);
                    if (i + 1 != N) {
                        blocks.push_back({vector<int>(), vector<pi>()});
                    }
                }
            }
            upd = 0;
        }
     
        // Find the block in which i belongs to and in which block it will go
        // First remove the element
        int prev = loc[pos];
        for (int i = 0; i < blocks.size(); i++) {
            if (blocks[i].positions.back() >= prev) {
                // Insert at previous block
                remove_from(i, prev);
                break;
            }
        }
     
        loc[pos] = y;
        // Then insert
        for (int i = 0; i < blocks.size(); i++) {
            if (blocks[i].positions.back() >= y || i == blocks.size() - 1) {
                // Insert at previous block
                insert_at(i, y);
                break;
            }
        }
     
        // Recalculate the photos
        pi ans = mp(0, 0);
        for (int b = 0; b < blocks.size(); b++) {
            pi nxt = calculate_block(b, ans.f);
     
            ans.f = nxt.f;
            ans.s += nxt.s;
        }
     
        return ans.s;
    }

Compilation message

elephants.cpp: In function 'int update(int, int)':
elephants.cpp:178:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Block>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  178 |         for (int i = 0; i < blocks.size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~
elephants.cpp:188:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Block>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  188 |         for (int i = 0; i < blocks.size(); i++) {
      |                         ~~^~~~~~~~~~~~~~~
elephants.cpp:189:54: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Block>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  189 |             if (blocks[i].positions.back() >= y || i == blocks.size() - 1) {
      |                                                    ~~^~~~~~~~~~~~~~~~~~~~
elephants.cpp:198:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<Block>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  198 |         for (int b = 0; b < blocks.size(); b++) {
      |                         ~~^~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 312 KB Output is correct
3 Correct 0 ms 340 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 312 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 1 ms 304 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 308 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 312 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 1 ms 304 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 308 KB Output is correct
7 Correct 619 ms 1488 KB Output is correct
8 Correct 855 ms 1604 KB Output is correct
9 Correct 2296 ms 2412 KB Output is correct
10 Correct 2419 ms 2456 KB Output is correct
11 Correct 2387 ms 2456 KB Output is correct
12 Correct 2769 ms 2808 KB Output is correct
13 Correct 2517 ms 2392 KB Output is correct

Subtask #4
47.0 / 47.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 312 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 1 ms 304 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 308 KB Output is correct
7 Correct 619 ms 1488 KB Output is correct
8 Correct 855 ms 1604 KB Output is correct
9 Correct 2296 ms 2412 KB Output is correct
10 Correct 2419 ms 2456 KB Output is correct
11 Correct 2387 ms 2456 KB Output is correct
12 Correct 2769 ms 2808 KB Output is correct
13 Correct 2517 ms 2392 KB Output is correct
14 Correct 1190 ms 2080 KB Output is correct
15 Correct 1500 ms 2168 KB Output is correct
16 Correct 4127 ms 3048 KB Output is correct
17 Correct 5345 ms 3972 KB Output is correct
18 Correct 5544 ms 3916 KB Output is correct
19 Correct 4385 ms 3392 KB Output is correct
20 Correct 5334 ms 3844 KB Output is correct
21 Correct 5345 ms 3800 KB Output is correct
22 Correct 4854 ms 3368 KB Output is correct

Subtask #5
0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 312 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 1 ms 304 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 308 KB Output is correct
7 Correct 619 ms 1488 KB Output is correct
8 Correct 855 ms 1604 KB Output is correct
9 Correct 2296 ms 2412 KB Output is correct
10 Correct 2419 ms 2456 KB Output is correct
11 Correct 2387 ms 2456 KB Output is correct
12 Correct 2769 ms 2808 KB Output is correct
13 Correct 2517 ms 2392 KB Output is correct
14 Correct 1190 ms 2080 KB Output is correct
15 Correct 1500 ms 2168 KB Output is correct
16 Correct 4127 ms 3048 KB Output is correct
17 Correct 5345 ms 3972 KB Output is correct
18 Correct 5544 ms 3916 KB Output is correct
19 Correct 4385 ms 3392 KB Output is correct
20 Correct 5334 ms 3844 KB Output is correct
21 Correct 5345 ms 3800 KB Output is correct
22 Correct 4854 ms 3368 KB Output is correct
23 Execution timed out 9032 ms 6168 KB Time limit exceeded
24 Halted 0 ms 0 KB -