Submission #625519

#	Time	Username	Problem	Language	Result	Execution time	Memory
625519		Ooops_sorry	Boarding Passes (BOI22_passes)	C++14	60 / 100	2083 ms	366912 KiB

passes

#include<bits/stdc++.h>

using namespace std;

mt19937 rnd(51);

#define ll long long
#define pb push_back
#define ld long double

const ld INF = 1e18;

//a * (a - 1) / 4

ld func(int a) {
    return (ld)a * (a - 1) / 4;
}

signed main() {
#ifdef LOCAL
    freopen("input.txt", "r", stdin);
#endif // LOCAL
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    string s;
    cin >> s;
    int n = s.size();
    vector<int> a(n);
    map<char, int> mp;
    for (int i = 0; i < s.size(); i++) {
        if (mp.count(s[i]) == 0) {
            mp[s[i]] = mp.size();
        }
        a[i] = mp[s[i]];
    }
    int g = mp.size();
    vector<ld> dp((1 << g), INF);
    vector<vector<int>> pos(g);
    vector<vector<vector<ll>>> L(g, vector<vector<ll>>(g, vector<ll>(n))), R(g, vector<vector<ll>>(g, vector<ll>(n)));
    for (int i = 0; i < n; i++) {
        pos[a[i]].pb(i);
    }
    for (int i = 0; i < g; i++) {
        for (int l = 0; l < g; l++) {
            ll cnt = 0, res = 0;
            for (int j = 0; j < n; j++) {
                if (i == a[j]) {
                    res += cnt;
                    L[i][l][j] = res;
                } else if (l == a[j]){
                    cnt++;
                }
            }
            cnt = 0, res = 0;
            for (int j = n - 1; j >= 0; j--) {
                if (i == a[j]) {
                    res += cnt;
                    R[i][l][j] = res;
                } else if (l == a[j]){
                    cnt++;
                }
            }
        }
    }
    dp[0] = 0;
    for (int i = 0; i < (1 << g); i++) {
        for (int j = 0; j < g; j++) {
            if (!(i & (1 << j))) {
                ld bst = func(pos[j].size());
                for (int k = 0; k < g; k++) {
                    if (i & (1 << k)) {
                        bst += R[j][k][pos[j][0]];
                    }
                }
                for (int k = 0; k < pos[j].size(); k++) {
                    ld val = func(k + 1) + func((int)(pos[j].size()) - k - 1);
                    for (int l = 0; l < g; l++) {
                        if (i & (1 << l)) {
                            val += L[j][l][pos[j][k]];
                            if (k + 1 < pos[j].size()) {
                                val += R[j][l][pos[j][k + 1]];
                            }
                        }
                    }
                    bst = min(bst, val);
                }
                dp[i + (1 << j)] = min(dp[i + (1 << j)], dp[i] + bst);
            }
        }
    }
    cout << setprecision(30) << fixed << dp[(1 << g) - 1] << endl;
    return 0;
}

Compilation message (stderr)

passes.cpp: In function 'int main()':
passes.cpp:30:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   30 |     for (int i = 0; i < s.size(); i++) {
      |                     ~~^~~~~~~~~~
passes.cpp:75:35: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |                 for (int k = 0; k < pos[j].size(); k++) {
      |                                 ~~^~~~~~~~~~~~~~~
passes.cpp:80:39: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   80 |                             if (k + 1 < pos[j].size()) {
      |                                 ~~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 25 / 25
• Subtask 3: 30 / 30
• Subtask 4: 0 / 40