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Submission #746705

# Submission time Handle Problem Language Result Execution time Memory
746705 2023-05-23T01:17:13 Z fishy15 Sorting (IOI15_sorting) C++17
100 / 100
 147 ms 20796 KB 
#include <iostream>
#include <vector>

#include "sorting.h"

using namespace std;

int findSwapPairs(int N, int S[], int M, int X[], int Y[], int P[], int Q[]) {
    int l = 0;
    int r = M;
    int ans = -1;

    auto check = [&](int m) {
        vector<int> nums(S, S + N);
        for (int i = 0; i < m; i++) {
            swap(nums[X[i]], nums[Y[i]]);
        }

        vector<bool> vis(N);
        int cycle_count = 0;

        for (int i = 0; i < N; i++) {
            if (!vis[i]) {
                cycle_count++;

                int cur = nums[i];
                while (cur != i) {
                    vis[cur] = true;
                    cur = nums[cur];
                }
            }
        }

        return N - cycle_count <= m;
    };

    while (l <= r) {
        int m = (l + r) / 2;
        if (check(m)) {
            ans = m;
            r = m - 1;
        } else {
            l = m + 1;
        }
    }

    vector<int> after_m(S, S + N);
    for (int i = 0; i < ans; i++) {
        swap(after_m[X[i]], after_m[Y[i]]);
    }

    vector<pair<int, int>> nums_to_swap;
    vector<bool> vis(N);

    for (int i = 0; i < N; i++) {
        if (!vis[i]) {
            int nxt = after_m[i];
            int pre = i;
            vis[i] = true;
            while (!vis[nxt]) {
                vis[nxt] = true;
                nums_to_swap.push_back({pre, nxt});
                pre = nxt;
                nxt = after_m[nxt];
            }
        }
    }

    while ((int) nums_to_swap.size() < ans) {
        nums_to_swap.push_back({0, 0});
    }

    vector<int> cur_p(S, S + N);
    vector<int> cur_inv(N);
    for (int i = 0; i < N; i++) {
        cur_inv[cur_p[i]] = i;
    }

    for (int i = 0; i < ans; i++) {
        // their swap
        auto t1 = cur_p[X[i]];
        auto t2 = cur_p[Y[i]];
        swap(cur_p[X[i]], cur_p[Y[i]]);
        swap(cur_inv[t1], cur_inv[t2]);

        // our swap
        auto [num1, num2] = nums_to_swap[i];
        auto idx1 = cur_inv[num1];
        auto idx2 = cur_inv[num2];

        P[i] = idx1;
        Q[i] = idx2;

        swap(cur_p[idx1], cur_p[idx2]);
        swap(cur_inv[num1], cur_inv[num2]);
    }

    return ans;
}

Subtask #1
8.0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 296 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 296 KB Output is correct

Subtask #2
12.0 / 12.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 296 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 296 KB Output is correct
8 Correct 1 ms 296 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 304 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct

Subtask #3
16.0 / 16.0

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

Subtask #4
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 296 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 1 ms 296 KB Output is correct
8 Correct 1 ms 296 KB Output is correct
9 Correct 1 ms 212 KB Output is correct
10 Correct 1 ms 304 KB Output is correct
11 Correct 1 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 212 KB Output is correct
14 Correct 1 ms 212 KB Output is correct
15 Correct 1 ms 304 KB Output is correct
16 Correct 1 ms 340 KB Output is correct
17 Correct 1 ms 340 KB Output is correct
18 Correct 1 ms 212 KB Output is correct
19 Correct 1 ms 212 KB Output is correct
20 Correct 0 ms 300 KB Output is correct
21 Correct 1 ms 468 KB Output is correct
22 Correct 1 ms 468 KB Output is correct
23 Correct 1 ms 440 KB Output is correct
24 Correct 2 ms 468 KB Output is correct
25 Correct 1 ms 440 KB Output is correct
26 Correct 2 ms 436 KB Output is correct
27 Correct 1 ms 468 KB Output is correct

Subtask #5
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 2 ms 504 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 440 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 2 ms 340 KB Output is correct
7 Correct 1 ms 440 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 1 ms 468 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 340 KB Output is correct

Subtask #6
26.0 / 26.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 468 KB Output is correct
2 Correct 2 ms 504 KB Output is correct
3 Correct 1 ms 468 KB Output is correct
4 Correct 1 ms 440 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 2 ms 340 KB Output is correct
7 Correct 1 ms 440 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 468 KB Output is correct
10 Correct 1 ms 468 KB Output is correct
11 Correct 2 ms 376 KB Output is correct
12 Correct 1 ms 468 KB Output is correct
13 Correct 1 ms 468 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 122 ms 18528 KB Output is correct
16 Correct 129 ms 19088 KB Output is correct
17 Correct 138 ms 19944 KB Output is correct
18 Correct 57 ms 15540 KB Output is correct
19 Correct 115 ms 17880 KB Output is correct
20 Correct 130 ms 18624 KB Output is correct
21 Correct 122 ms 18520 KB Output is correct
22 Correct 119 ms 15396 KB Output is correct
23 Correct 132 ms 20796 KB Output is correct
24 Correct 142 ms 20340 KB Output is correct
25 Correct 137 ms 20184 KB Output is correct
26 Correct 124 ms 18492 KB Output is correct
27 Correct 109 ms 17904 KB Output is correct
28 Correct 141 ms 20380 KB Output is correct
29 Correct 136 ms 19732 KB Output is correct
30 Correct 83 ms 18108 KB Output is correct
31 Correct 137 ms 20132 KB Output is correct
32 Correct 130 ms 19892 KB Output is correct
33 Correct 136 ms 20536 KB Output is correct
34 Correct 133 ms 20320 KB Output is correct
35 Correct 115 ms 17744 KB Output is correct
36 Correct 55 ms 16744 KB Output is correct
37 Correct 147 ms 20484 KB Output is correct
38 Correct 140 ms 20064 KB Output is correct
39 Correct 135 ms 19572 KB Output is correct