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Submission #839453

# Submission time Handle Problem Language Result Execution time Memory
839453 2023-08-30T04:44:30 Z pdm Examination (JOI19_examination) C++14
100 / 100
 969 ms 11856 KB 
/*
JOI 2019 Examination
- The main idea is to use MO's algorithm
- Keep two pointers: one on S and one on T
- We can use an unordered map to check for students that satisfy both A and B
- Next, we can coordinate compress the sum of scores and then use a BIT to query
  the number of students satisfying A and B that also satisfy C
- Complexity: O(N (sqrt N + log N))
*/

#include <bits/stdc++.h>
typedef long long ll;
using namespace std;

#include <ext/pb_ds/assoc_container.hpp>
using namespace __gnu_pbds;

const int N = 100000, BCKT = 750;

int n, q;
int s[N], t[N], sums[N], sum_ptr[N];
pair<int, int> by_s[N], by_t[N];
vector<tuple<int, int, int, int>> queries[N / BCKT + 1];
int bit[N + 1];
int ans[N];

void update(int pos, int val) {
    for (; pos <= n; pos += pos & -pos) bit[pos] += val;
}

int query(int l, int r) {
    int ans = 0;
    for (; r; r -= r & -r) ans += bit[r];
    for (l--; l; l -= l & -l) ans -= bit[l];
    return ans;
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin >> n >> q;
    for (int i = 0; i < n; i++) {
        cin >> s[i] >> t[i];
        sums[i] = s[i] + t[i];
        by_s[i] = {s[i], i};
        by_t[i] = {t[i], i};
    }
    sort(sums, sums + n);
    for (int i = 0; i < n; i++) {
        sum_ptr[i] = lower_bound(sums, sums + n, s[i] + t[i]) - sums + 1;
    }
    sort(by_s, by_s + n);
    sort(by_t, by_t + n);
    for (int i = 0; i < q; i++) {
        int a, b, c;
        cin >> a >> b >> c;
        a = lower_bound(by_s, by_s + n, make_pair(a, 0)) - by_s;
        b = lower_bound(by_t, by_t + n, make_pair(b, 0)) - by_t;
        c = lower_bound(sums, sums + n, c) - sums + 1;
        queries[a / BCKT].push_back(tuple<int, int, int, int>(a, b, c, i));
    }

    gp_hash_table<int, int> good_cnt;
    for (int i = N / BCKT, sptr = n, tptr = n; ~i; i--) {
        sort(queries[i].begin(), queries[i].end(), [](tuple<int, int, int, int> A, tuple<int, int, int, int> B) {
            return get<1>(A) > get<1>(B);
        });
        for (tuple<int, int, int, int> j : queries[i]) {
            int a, b, c, idx;
            tie(a, b, c, idx) = j;

            while (sptr > a) {
                good_cnt[by_s[sptr - 1].second]++;
                if (good_cnt[by_s[sptr - 1].second] == 2) {
                    update(sum_ptr[by_s[sptr - 1].second], 1);
                }
                sptr--;
            }
            while (sptr < a) {
                good_cnt[by_s[sptr].second]--;
                if (good_cnt[by_s[sptr].second] == 1) {
                    update(sum_ptr[by_s[sptr].second], -1);
                }
                sptr++;
            }
            while (tptr > b) {
                good_cnt[by_t[tptr - 1].second]++;
                if (good_cnt[by_t[tptr - 1].second] == 2) {
                    update(sum_ptr[by_t[tptr - 1].second], 1);
                }
                tptr--;
            }
            while (tptr < b) {
                good_cnt[by_t[tptr].second]--;
                if (good_cnt[by_t[tptr].second] == 1) {
                    update(sum_ptr[by_t[tptr].second], -1);
                }
                tptr++;
            }
            ans[idx] = query(c, n);
        }
    }

    for (int i = 0; i < q; i++) cout << ans[i] << '\n';
    return 0;
}

Subtask #1
2.0 / 2.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 9 ms 668 KB Output is correct
8 Correct 9 ms 748 KB Output is correct
9 Correct 9 ms 748 KB Output is correct
10 Correct 10 ms 724 KB Output is correct
11 Correct 8 ms 636 KB Output is correct
12 Correct 7 ms 724 KB Output is correct
13 Correct 9 ms 724 KB Output is correct
14 Correct 9 ms 744 KB Output is correct
15 Correct 9 ms 724 KB Output is correct
16 Correct 3 ms 724 KB Output is correct
17 Correct 8 ms 748 KB Output is correct
18 Correct 2 ms 724 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 938 ms 11744 KB Output is correct
2 Correct 946 ms 11800 KB Output is correct
3 Correct 945 ms 11772 KB Output is correct
4 Correct 746 ms 11832 KB Output is correct
5 Correct 139 ms 11188 KB Output is correct
6 Correct 100 ms 11064 KB Output is correct
7 Correct 470 ms 11300 KB Output is correct
8 Correct 529 ms 11760 KB Output is correct
9 Correct 499 ms 11288 KB Output is correct
10 Correct 93 ms 10740 KB Output is correct
11 Correct 687 ms 11496 KB Output is correct
12 Correct 52 ms 11712 KB Output is correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 938 ms 11744 KB Output is correct
2 Correct 946 ms 11800 KB Output is correct
3 Correct 945 ms 11772 KB Output is correct
4 Correct 746 ms 11832 KB Output is correct
5 Correct 139 ms 11188 KB Output is correct
6 Correct 100 ms 11064 KB Output is correct
7 Correct 470 ms 11300 KB Output is correct
8 Correct 529 ms 11760 KB Output is correct
9 Correct 499 ms 11288 KB Output is correct
10 Correct 93 ms 10740 KB Output is correct
11 Correct 687 ms 11496 KB Output is correct
12 Correct 52 ms 11712 KB Output is correct
13 Correct 956 ms 11812 KB Output is correct
14 Correct 961 ms 11728 KB Output is correct
15 Correct 928 ms 11800 KB Output is correct
16 Correct 753 ms 11800 KB Output is correct
17 Correct 155 ms 11280 KB Output is correct
18 Correct 112 ms 11384 KB Output is correct
19 Correct 953 ms 11800 KB Output is correct
20 Correct 969 ms 11816 KB Output is correct
21 Correct 636 ms 11648 KB Output is correct
22 Correct 92 ms 10724 KB Output is correct
23 Correct 707 ms 11612 KB Output is correct
24 Correct 51 ms 11616 KB Output is correct

Subtask #4
57.0 / 57.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 0 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 9 ms 668 KB Output is correct
8 Correct 9 ms 748 KB Output is correct
9 Correct 9 ms 748 KB Output is correct
10 Correct 10 ms 724 KB Output is correct
11 Correct 8 ms 636 KB Output is correct
12 Correct 7 ms 724 KB Output is correct
13 Correct 9 ms 724 KB Output is correct
14 Correct 9 ms 744 KB Output is correct
15 Correct 9 ms 724 KB Output is correct
16 Correct 3 ms 724 KB Output is correct
17 Correct 8 ms 748 KB Output is correct
18 Correct 2 ms 724 KB Output is correct
19 Correct 938 ms 11744 KB Output is correct
20 Correct 946 ms 11800 KB Output is correct
21 Correct 945 ms 11772 KB Output is correct
22 Correct 746 ms 11832 KB Output is correct
23 Correct 139 ms 11188 KB Output is correct
24 Correct 100 ms 11064 KB Output is correct
25 Correct 470 ms 11300 KB Output is correct
26 Correct 529 ms 11760 KB Output is correct
27 Correct 499 ms 11288 KB Output is correct
28 Correct 93 ms 10740 KB Output is correct
29 Correct 687 ms 11496 KB Output is correct
30 Correct 52 ms 11712 KB Output is correct
31 Correct 956 ms 11812 KB Output is correct
32 Correct 961 ms 11728 KB Output is correct
33 Correct 928 ms 11800 KB Output is correct
34 Correct 753 ms 11800 KB Output is correct
35 Correct 155 ms 11280 KB Output is correct
36 Correct 112 ms 11384 KB Output is correct
37 Correct 953 ms 11800 KB Output is correct
38 Correct 969 ms 11816 KB Output is correct
39 Correct 636 ms 11648 KB Output is correct
40 Correct 92 ms 10724 KB Output is correct
41 Correct 707 ms 11612 KB Output is correct
42 Correct 51 ms 11616 KB Output is correct
43 Correct 967 ms 11756 KB Output is correct
44 Correct 951 ms 11856 KB Output is correct
45 Correct 960 ms 11612 KB Output is correct
46 Correct 751 ms 11820 KB Output is correct
47 Correct 160 ms 11160 KB Output is correct
48 Correct 102 ms 10920 KB Output is correct
49 Correct 440 ms 11108 KB Output is correct
50 Correct 593 ms 11636 KB Output is correct
51 Correct 513 ms 11260 KB Output is correct
52 Correct 114 ms 10724 KB Output is correct
53 Correct 695 ms 11604 KB Output is correct