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Submission #585295

# Submission time Handle Problem Language Result Execution time Memory
585295 2022-06-28T14:49:03 Z _martynas Boarding Passes (BOI22_passes) C++11
55 / 100
 145 ms 2596 KB 
#include <bits/stdc++.h>

using namespace std;

using ll = long long;

const int MXG = 15;
const ll INF = 1e17;

string s;
int n;
vector<ll> A[MXG];
// pref[i][j][k] -> i after j cost from left at k
vector<ll> pref[MXG][MXG];
// suff[i][j][k] -> i after j cost from right at k
vector<ll> suff[MXG][MXG];
ll dp[1 << MXG];
bool visited[1 << MXG];

void init()
{
    // pref
    for(int i = 0; i < MXG; i++) {
        for(int j = 0; j < MXG; j++) {
            if(i == j || A[i].empty() || A[j].empty()) continue;
            int r = 0;
            int cost = 0;
            for(int k = 0; k < A[i].size(); k++) {
                while(r < A[j].size() && A[j][r] < A[i][k]) {
                    r++;
                }
                cost += r;
                pref[i][j].push_back(4*cost);
            }
        }
    }
    // suff
    for(int i = 0; i < MXG; i++) {
        for(int j = 0; j < MXG; j++) {
            if(i == j || A[i].empty() || A[j].empty()) continue;
            int r = A[j].size()-1;
            int cost = 0;
            for(int k = A[i].size()-1; k >= 0; k--) {
                while(r >= 0 && A[j][r] > A[i][k]) {
                    r--;
                }
                cost += A[j].size()-1-r;
                suff[i][j].insert(suff[i][j].begin(), 4*cost);
            }
        }
    }
}

ll cost(int group, int bitmask, int split)
{
    ll sum = 0;
    for(int g = 0; g < MXG; g++) {
        if(((bitmask >> g) & 1) == 0 || A[g].empty() || g == group) continue;
        //cerr << "left: " << (split > -1 ? pref[group][g][split] : 0) << "\n";
        sum += split > -1 ? pref[group][g][split] : 0;
        //cerr << "right: " << (split+1 < A[group].size() ? suff[group][g][split+1] : 0) << "\n";
        sum += split+1 < A[group].size() ? suff[group][g][split+1] : 0;
    }
    if(split > 0) {
        //cerr << "left chance: " << split*(split+1) << "\n";
        sum += split*(split+1); // chance to collide between on the left
    }
    ll cnt = A[group].size() - (split+1);
    if(cnt > 1) {
        //cerr << "right chance: " << cnt*(cnt-1) << "\n";
        sum += cnt*(cnt-1); // chance to collide between on the right
    }
    return sum;
}

ll recur(int bitmask)
{
    if(bitmask == 0) {
        return 0;
    }
    if(visited[bitmask]) {
        return dp[bitmask];
    }
    visited[bitmask] = true;
    ll mn = INF;
    for(int g = 0; g < MXG; g++) {
        if(((bitmask >> g) & 1) == 0) continue;
        int bits = bitmask - (1 << g);
        ll initial = recur(bits);
        if(A[g].empty()) {
            mn = min(mn, initial);
            continue;
        }
        int l = -1, r = A[g].size()-1;
        while(l < r) {
            int mid = l == -1 && r == 0 ? -1 : (l + r) / 2;
            ll a = cost(g, bits, mid);
            ll b = cost(g, bits, mid+1);
            if(a < b) {
                r = mid;
            }
            else {
                l = mid+1;
            }
        }
        mn = min(mn, initial + cost(g, bits, l));
    }
    dp[bitmask] = mn;
    return dp[bitmask];
}

int main()
{
// For some reason I have to comment this:
// ============================
//    cin.tie(0);
//    ios::sync_with_stdio(0);
// ============================
    //s = string(899, 'A');
    getline(cin, s);
    n = s.size();

    for(int i = 0; i < n; i++) {
        A[s[i]-'A'].push_back(i);
    }
    init();
    // the hell is this grader?
    ll ans = recur(0x7fff);
    cout << ans / 4;
    if(ans % 4 == 1) {
        cout << ".25";
    }
    else if(ans % 4 == 2) {
        cout << ".5";
    }
    else if(ans % 4 == 3) {
        cout << ".75";
    }

    return 0;
}
/*
AACCAA
HEHEHEHIHILOL
ONMLKJIHGFEDCBAABCDEFGHIJKLMNO
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

*/

Compilation message

passes.cpp: In function 'void init()':
passes.cpp:28:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   28 |             for(int k = 0; k < A[i].size(); k++) {
      |                            ~~^~~~~~~~~~~~~
passes.cpp:29:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   29 |                 while(r < A[j].size() && A[j][r] < A[i][k]) {
      |                       ~~^~~~~~~~~~~~~
passes.cpp: In function 'll cost(int, int, int)':
passes.cpp:62:24: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |         sum += split+1 < A[group].size() ? suff[group][g][split+1] : 0;
      |                ~~~~~~~~^~~~~~~~~~~~~~~~~

Subtask #1
0 / 5.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 596 KB Output is correct
2 Correct 6 ms 600 KB Output is correct
3 Correct 5 ms 596 KB Output is correct
4 Correct 7 ms 572 KB Output is correct
5 Correct 10 ms 616 KB Output is correct
6 Correct 16 ms 1520 KB Output is correct
7 Incorrect 17 ms 1540 KB Output isn't correct
8 Halted 0 ms 0 KB -

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 596 KB Output is correct
2 Correct 8 ms 596 KB Output is correct
3 Correct 33 ms 596 KB Output is correct
4 Correct 34 ms 608 KB Output is correct
5 Correct 20 ms 612 KB Output is correct
6 Correct 18 ms 604 KB Output is correct
7 Correct 31 ms 596 KB Output is correct
8 Correct 23 ms 596 KB Output is correct
9 Correct 27 ms 596 KB Output is correct
10 Correct 24 ms 596 KB Output is correct
11 Correct 24 ms 604 KB Output is correct
12 Correct 24 ms 604 KB Output is correct
13 Correct 25 ms 596 KB Output is correct
14 Correct 26 ms 600 KB Output is correct
15 Correct 24 ms 596 KB Output is correct
16 Correct 25 ms 600 KB Output is correct
17 Correct 27 ms 596 KB Output is correct

Subtask #3
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 8 ms 596 KB Output is correct
2 Correct 8 ms 596 KB Output is correct
3 Correct 33 ms 596 KB Output is correct
4 Correct 34 ms 608 KB Output is correct
5 Correct 20 ms 612 KB Output is correct
6 Correct 18 ms 604 KB Output is correct
7 Correct 31 ms 596 KB Output is correct
8 Correct 23 ms 596 KB Output is correct
9 Correct 27 ms 596 KB Output is correct
10 Correct 24 ms 596 KB Output is correct
11 Correct 24 ms 604 KB Output is correct
12 Correct 24 ms 604 KB Output is correct
13 Correct 25 ms 596 KB Output is correct
14 Correct 26 ms 600 KB Output is correct
15 Correct 24 ms 596 KB Output is correct
16 Correct 25 ms 600 KB Output is correct
17 Correct 27 ms 596 KB Output is correct
18 Correct 8 ms 596 KB Output is correct
19 Correct 12 ms 596 KB Output is correct
20 Correct 36 ms 600 KB Output is correct
21 Correct 37 ms 596 KB Output is correct
22 Correct 21 ms 572 KB Output is correct
23 Correct 22 ms 608 KB Output is correct
24 Correct 28 ms 596 KB Output is correct
25 Correct 23 ms 600 KB Output is correct
26 Correct 26 ms 596 KB Output is correct
27 Correct 23 ms 600 KB Output is correct
28 Correct 24 ms 600 KB Output is correct
29 Correct 24 ms 596 KB Output is correct
30 Correct 26 ms 600 KB Output is correct
31 Correct 27 ms 608 KB Output is correct
32 Correct 25 ms 596 KB Output is correct
33 Correct 25 ms 600 KB Output is correct
34 Correct 25 ms 604 KB Output is correct
35 Correct 12 ms 756 KB Output is correct
36 Correct 13 ms 836 KB Output is correct
37 Correct 98 ms 2388 KB Output is correct
38 Correct 119 ms 2136 KB Output is correct
39 Correct 145 ms 2260 KB Output is correct
40 Correct 100 ms 2148 KB Output is correct
41 Correct 97 ms 2516 KB Output is correct
42 Correct 120 ms 2580 KB Output is correct
43 Correct 104 ms 2452 KB Output is correct
44 Correct 96 ms 2552 KB Output is correct
45 Correct 104 ms 2556 KB Output is correct
46 Correct 119 ms 2596 KB Output is correct

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 596 KB Output is correct
2 Correct 6 ms 600 KB Output is correct
3 Correct 5 ms 596 KB Output is correct
4 Correct 7 ms 572 KB Output is correct
5 Correct 10 ms 616 KB Output is correct
6 Correct 16 ms 1520 KB Output is correct
7 Incorrect 17 ms 1540 KB Output isn't correct
8 Halted 0 ms 0 KB -