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Submission #56440

# Submission time Handle Problem Language Result Execution time Memory
56440 2018-07-11T10:36:52 Z aquablitz11 Dancing Elephants (IOI11_elephants) C++14
100 / 100
 8405 ms 125152 KB 
#include <bits/stdc++.h>
#include "elephants.h"
using namespace std;

const int N = 150010;
const int SN = 390;

int n, sn, l, X[N];
vector<int> elep[SN], cnt[N], rbnd[N];

int find_bucket(int x)
{
    for (int i = 0; i < sn; ++i) {
        if (!elep[i].empty() && x <= elep[i].back())
            return i;
    }
    return sn-1;
}

void process_bucket(int p)
{
    //fprintf(stderr, "process_bucket(%d):\n", p);
    int n = elep[p].size();
    cnt[p].resize(n);
    rbnd[p].resize(n);
    for (int i = n-1, j = n-1; i >= 0; --i) {
        while (elep[p][j]-elep[p][i] > l)
            --j;
        cnt[p][i] = j == n-1 ? 1 : (1 + cnt[p][j+1]);
        rbnd[p][i] = j == n-1 ? (elep[p][i]+l) : rbnd[p][j+1];
    }
    /*for (int i = 0; i < n; ++i) {
        if (i != 0) fprintf(stderr, " ");
        fprintf(stderr, "%3d", elep[p][i]);
    }
    fprintf(stderr, "\n");
    for (int i = 0; i < n; ++i) {
        if (i != 0) fprintf(stderr, " ");
        fprintf(stderr, "%3d", cnt[p][i]);
    }
    fprintf(stderr, "\n");
    for (int i = 0; i < n; ++i) {
        if (i != 0) fprintf(stderr, " ");
        fprintf(stderr, "%3d", rbnd[p][i]);
    }
    fprintf(stderr, "\n");
    fprintf(stderr, "\n");*/
}

void process_all()
{
    //fprintf(stderr, "process_all():\n");
    vector<int> X(::X, ::X+n);
    sort(X.begin(), X.end());
    for (int i = 0; i < sn; ++i) {
        elep[i].clear();
        elep[i].reserve(3*sn);
    }
    for (int i = 0; i < n; ++i) {
        int b = i/sn;
        if (b >= sn) b = sn-1;
        elep[b].push_back(X[i]);
        //fprintf(stderr, "add elephant X = %d to block %d\n", X[i], b);
    }
    //fprintf(stderr, "\n");
    for (int i = 0; i < sn; ++i)
        process_bucket(i);
}

void init(int n, int l, int X[])
{
    ::n = n, ::l = l, ::sn = sqrt(n);
    for (int i = 0; i < n; ++i)
        ::X[i] = X[i];
    process_all();
}

int cnt_upd = 0;
bool force = false;
bool skip = false;
int update(int i, int y)
{
    //fprintf(stderr, "update(%d, %d):\n", i, y);
    if (force || (!skip && ((++cnt_upd) % sn == 0))) {
        X[i] = y;
        process_all();
    } else {
        int bx = find_bucket(X[i]);
        int by = find_bucket(y);
        elep[bx].erase(find(elep[bx].begin(), elep[bx].end(), X[i]));
        elep[by].insert(lower_bound(elep[by].begin(), elep[by].end(), y), y);
        //fprintf(stderr, "%d is in bucket %d, %d is in bucket %d\n", X[i], bx, y, by);
        process_bucket(bx);
        if (bx != by) process_bucket(by);
        X[i] = y;
    }
    //fprintf(stderr, "\n");

    int ans = 0, last = -1;
    for (int b = 0; b < sn; ++b) {
        int i = upper_bound(elep[b].begin(), elep[b].end(), last) - elep[b].begin();
        if (i < elep[b].size()) {
            //fprintf(stderr, "block %d, got elephant %d: %d %d %d\n", b, i, elep[b][i], cnt[b][i], rbnd[b][i]);
            ans += cnt[b][i];
            last = rbnd[b][i];
        }
    }

    return ans;
}

Compilation message

elephants.cpp: In function 'int update(int, int)':
elephants.cpp:102:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (i < elep[b].size()) {
             ~~^~~~~~~~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB Output is correct
2 Correct 9 ms 7524 KB Output is correct
3 Correct 9 ms 7524 KB Output is correct

Subtask #2
16.0 / 16.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB Output is correct
2 Correct 9 ms 7524 KB Output is correct
3 Correct 9 ms 7524 KB Output is correct
4 Correct 10 ms 7524 KB Output is correct
5 Correct 9 ms 7524 KB Output is correct
6 Correct 15 ms 7560 KB Output is correct

Subtask #3
24.0 / 24.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB Output is correct
2 Correct 9 ms 7524 KB Output is correct
3 Correct 9 ms 7524 KB Output is correct
4 Correct 10 ms 7524 KB Output is correct
5 Correct 9 ms 7524 KB Output is correct
6 Correct 15 ms 7560 KB Output is correct
7 Correct 357 ms 8712 KB Output is correct
8 Correct 438 ms 9864 KB Output is correct
9 Correct 700 ms 12728 KB Output is correct
10 Correct 1219 ms 13896 KB Output is correct
11 Correct 1221 ms 15160 KB Output is correct
12 Correct 1490 ms 16908 KB Output is correct
13 Correct 1033 ms 17732 KB Output is correct

Subtask #4
47.0 / 47.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB Output is correct
2 Correct 9 ms 7524 KB Output is correct
3 Correct 9 ms 7524 KB Output is correct
4 Correct 10 ms 7524 KB Output is correct
5 Correct 9 ms 7524 KB Output is correct
6 Correct 15 ms 7560 KB Output is correct
7 Correct 357 ms 8712 KB Output is correct
8 Correct 438 ms 9864 KB Output is correct
9 Correct 700 ms 12728 KB Output is correct
10 Correct 1219 ms 13896 KB Output is correct
11 Correct 1221 ms 15160 KB Output is correct
12 Correct 1490 ms 16908 KB Output is correct
13 Correct 1033 ms 17732 KB Output is correct
14 Correct 774 ms 18616 KB Output is correct
15 Correct 676 ms 20280 KB Output is correct
16 Correct 2070 ms 23204 KB Output is correct
17 Correct 2702 ms 25888 KB Output is correct
18 Correct 2828 ms 27876 KB Output is correct
19 Correct 1765 ms 29448 KB Output is correct
20 Correct 2557 ms 32144 KB Output is correct
21 Correct 2302 ms 34316 KB Output is correct
22 Correct 2061 ms 35160 KB Output is correct

Subtask #5
3.0 / 3.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 7416 KB Output is correct
2 Correct 9 ms 7524 KB Output is correct
3 Correct 9 ms 7524 KB Output is correct
4 Correct 10 ms 7524 KB Output is correct
5 Correct 9 ms 7524 KB Output is correct
6 Correct 15 ms 7560 KB Output is correct
7 Correct 357 ms 8712 KB Output is correct
8 Correct 438 ms 9864 KB Output is correct
9 Correct 700 ms 12728 KB Output is correct
10 Correct 1219 ms 13896 KB Output is correct
11 Correct 1221 ms 15160 KB Output is correct
12 Correct 1490 ms 16908 KB Output is correct
13 Correct 1033 ms 17732 KB Output is correct
14 Correct 774 ms 18616 KB Output is correct
15 Correct 676 ms 20280 KB Output is correct
16 Correct 2070 ms 23204 KB Output is correct
17 Correct 2702 ms 25888 KB Output is correct
18 Correct 2828 ms 27876 KB Output is correct
19 Correct 1765 ms 29448 KB Output is correct
20 Correct 2557 ms 32144 KB Output is correct
21 Correct 2302 ms 34316 KB Output is correct
22 Correct 2061 ms 35160 KB Output is correct
23 Correct 4581 ms 44480 KB Output is correct
24 Correct 4359 ms 49620 KB Output is correct
25 Correct 3940 ms 54224 KB Output is correct
26 Correct 5365 ms 58724 KB Output is correct
27 Correct 6324 ms 63600 KB Output is correct
28 Correct 1261 ms 63600 KB Output is correct
29 Correct 1252 ms 65060 KB Output is correct
30 Correct 1275 ms 67976 KB Output is correct
31 Correct 1197 ms 70912 KB Output is correct
32 Correct 6412 ms 79840 KB Output is correct
33 Correct 6268 ms 83600 KB Output is correct
34 Correct 6034 ms 88408 KB Output is correct
35 Correct 4701 ms 94664 KB Output is correct
36 Correct 3318 ms 97760 KB Output is correct
37 Correct 7790 ms 103840 KB Output is correct
38 Correct 6548 ms 106268 KB Output is correct
39 Correct 5486 ms 111052 KB Output is correct
40 Correct 6190 ms 114668 KB Output is correct
41 Correct 8246 ms 120352 KB Output is correct
42 Correct 8405 ms 125152 KB Output is correct