Submission #580168

#	Time	Username	Problem	Language	Result	Execution time	Memory
580168		Elias	Boarding Passes (BOI22_passes)	C++17	60 / 100	498 ms	1048576 KiB

passes

#include <bits/stdc++.h>

#ifndef _DEBUG
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx")
#endif

using namespace std;

#define int int64_t

signed main()
{
    cin.tie(0);
    ios_base::sync_with_stdio(false);

    string s;
    cin >> s;

    int n = s.size();
    int g = *max_element(s.begin(), s.end()) - 'A' + 1;

    vector<int> a(n);
    vector<vector<int>> pos(g);

    for (int i = 0; i < n; i++)
        pos[a[i] = s[i] - 'A'].push_back(i);

    vector<vector<int>> prefix(1 << g, vector<int>(n));
    vector<vector<int>> suffix(1 << g, vector<int>(n));

    for (int k = 0; k < 1 << g; k++)
    {
        for (int i = 1; i < n; i++)
            prefix[k][i] = prefix[k][i - 1] + bool(1 << a[i - 1] & k);
        for (int i = n - 2; i >= 0; i--)
            suffix[k][i] = suffix[k][i + 1] + bool(1 << a[i + 1] & k);
    }

    vector<int> dp(1 << g, 1e20);
    dp[0] = 0;

    for (int b = 1; b < 1 << g; b++)
    {
        for (int i = 0; i < g; i++)
        {
            if (!(b & (1 << i)))
                continue;

            int cost = 0;

            for (int p : pos[i])
            {
                cost += min(2 * prefix[b][p] - prefix[(1 << i)][p], 2 * suffix[b][p] - suffix[(1 << i)][p]);
            }

            dp[b] = min(dp[b], dp[b ^ (1 << i)] + cost);
        }
    }

    cout << setprecision(15) << dp.back() * 0.5;
}

Compilation message (stderr)

passes.cpp: In function 'int main()':
passes.cpp:41:28: warning: overflow in conversion from 'double' to 'std::vector<long int>::value_type' {aka 'long int'} changes value from '1.0e+20' to '9223372036854775807' [-Woverflow]
   41 |     vector<int> dp(1 << g, 1e20);
      |                            ^~~~

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