Submission #1102687

# Submission time Handle Problem Language Result Execution time Memory
1102687 2024-10-18T15:53:35 Z toast12 Group Photo (JOI21_ho_t3) C++14
5 / 100
368 ms 428 KB
#include <bits/stdc++.h>
using namespace std;

const int INF = 1e9;

int n;
vector<int> idx;

int cost(vector<int> &p) {
    // check if the arrangement is valid
    for (int i = 0; i < n-1; i++) {
        if (p[i] >= p[i+1]+2) return INF;
    }
    int res = 0;
    for (int i = 0; i < n; i++) {
        for (int j = i+1; j < n; j++) {
            if (idx[p[j]] < idx[p[i]]) res++;
        }
    }
    return res;
}

int main() {
    // n <= 20
    cin >> n;
    idx.resize(n+1);
    vector<int> h(n);
    for (int i = 0; i < n; i++) {
        cin >> h[i];
        idx[h[i]] = i;
    }
    int ans = INT_MAX;
    for (int mask = 0; mask < (1<<n); mask++) {
        vector<int> flip;
        for (int i = 0; i < n; i++) {
            if (mask & (1<<i)) flip.push_back(i);
        }
        if (flip.size() == 0 || (flip.size() > 0 && flip[0] == 0)) continue;
        vector<int> p(n);
        iota(p.begin(), p.end(), 1);
        int prev = 0;
        for (int i = 0; i < flip.size(); i++) {
            reverse(p.begin()+prev, p.begin()+flip[i]);
            prev = flip[i];
        }
        reverse(p.begin()+prev, p.end());
        ans = min(ans, cost(p));
        prev = 0;
        for (int i = 0; i < flip.size(); i++) {
            reverse(p.begin()+prev, p.begin()+flip[i]);
            prev = flip[i];
        }
        reverse(p.begin()+prev, p.end());
    }
    cout << ans << '\n';
    return 0;
}

Compilation message

Main.cpp: In function 'int main()':
Main.cpp:42:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for (int i = 0; i < flip.size(); i++) {
      |                         ~~^~~~~~~~~~~~~
Main.cpp:49:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |         for (int i = 0; i < flip.size(); i++) {
      |                         ~~^~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 352 KB Output is correct
4 Correct 1 ms 352 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 352 KB Output is correct
4 Correct 1 ms 352 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 91 ms 428 KB Output is correct
12 Correct 169 ms 340 KB Output is correct
13 Correct 179 ms 340 KB Output is correct
14 Correct 355 ms 428 KB Output is correct
15 Correct 368 ms 340 KB Output is correct
16 Correct 354 ms 340 KB Output is correct
17 Incorrect 342 ms 424 KB Output isn't correct
18 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 352 KB Output is correct
4 Correct 1 ms 352 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 91 ms 428 KB Output is correct
12 Correct 169 ms 340 KB Output is correct
13 Correct 179 ms 340 KB Output is correct
14 Correct 355 ms 428 KB Output is correct
15 Correct 368 ms 340 KB Output is correct
16 Correct 354 ms 340 KB Output is correct
17 Incorrect 342 ms 424 KB Output isn't correct
18 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 352 KB Output is correct
4 Correct 1 ms 352 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 91 ms 428 KB Output is correct
12 Correct 169 ms 340 KB Output is correct
13 Correct 179 ms 340 KB Output is correct
14 Correct 355 ms 428 KB Output is correct
15 Correct 368 ms 340 KB Output is correct
16 Correct 354 ms 340 KB Output is correct
17 Incorrect 342 ms 424 KB Output isn't correct
18 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 1 ms 340 KB Output is correct
3 Correct 1 ms 352 KB Output is correct
4 Correct 1 ms 352 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 1 ms 340 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 1 ms 340 KB Output is correct
11 Correct 91 ms 428 KB Output is correct
12 Correct 169 ms 340 KB Output is correct
13 Correct 179 ms 340 KB Output is correct
14 Correct 355 ms 428 KB Output is correct
15 Correct 368 ms 340 KB Output is correct
16 Correct 354 ms 340 KB Output is correct
17 Incorrect 342 ms 424 KB Output isn't correct
18 Halted 0 ms 0 KB -