Submission #860460

#	Time	Username	Problem	Language	Result	Execution time	Memory
860460		meliodasssf	Bajka (COCI20_bajka)	C++17	70 / 70	7 ms	4948 KiB

bajka

#include <bits/stdc++.h> //hi
using namespace std;

#define endl '\n'

int n,m;
string A,B;
int L[100010],R[100010];

void in()
{
    cin >> n >> m;
    cin >> A >> B;
    A = " " + A;
    B = " " + B;
    // for (int i=1; i<=n; i++) cout << A[i] << ' ' ; cout << endl;
    // for (int i=1; i<=n; i++) cout << B[i] << ' ' ; cout << endl;
}
map<char,int> mp;
void set_up()
{
    for(int i = 1; i <= n; i++)
    {
        if(mp.find(A[i]) != mp.end())
            L[i] = mp[A[i]];
        mp[A[i]] = i;
    }
    mp.clear();
    for(int i = n; i >= 1; i--)
    {
        if(mp.find(A[i]) != mp.end())
            R[i] = mp[A[i]];
        mp[A[i]] = i;
    }
    mp.clear();
    // for (int i=1; i<=n; i++) cout << L[i] << ' ' ; cout << endl;
    // for (int i=1; i<=n; i++) cout << R[i] << ' ' ; cout << endl;
}

long long dp[1010][1010];
bool visited[1010][1010];
 
struct path
{
    pair<int,int> s;
    long long len;
};
 
bool operator < (const path &a, const path &b)
{
    return a.len > b.len;
}
 
void dijkstra()
{
    priority_queue <path> pq;
 
    for (int i=1; i<=n; i++)
    {
        if(A[i] == B[1])
        {
            pq.push(path{{1, i}, 0});
        }
    }
    while(pq.empty() == false)
    {
        path p = pq.top();
        pq.pop();
        if(visited[p.s.first][p.s.second] == true) continue;
        visited[p.s.first][p.s.second] = true;
        dp[p.s.first][p.s.second] = p.len;
        if(p.s.first == m) continue;
 
        if(p.s.second > 1 && A[p.s.second - 1] == B[p.s.first + 1] && visited[p.s.first + 1][p.s.second - 1] == false)
        {
            pq.push(path{{p.s.first + 1, p.s.second - 1}, p.len + 1});
        }
        if(p.s.second < n && A[p.s.second + 1] == B[p.s.first + 1] && visited[p.s.first + 1][p.s.second + 1] == false)
        {
            pq.push(path{{p.s.first + 1, p.s.second + 1}, p.len + 1});
        }
        int pos1 = L[p.s.second];
        int pos2 = R[p.s.second];
        if(pos1 != 0 && visited[p.s.first][pos1] == false)
        {
            pq.push(path{{p.s.first, pos1}, p.len + abs(p.s.second - pos1)});
        }
        if(pos2 != 0 && visited[p.s.first][pos2] == false)
        {
            pq.push(path{{p.s.first, pos2}, p.len + abs(p.s.second - pos2)});
        }
    }
}

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

    dijkstra();
    long long res = LLONG_MAX;
    for (int i=1; i<=n; i++)
    {
        if(visited[m][i] == true)
        {
            res = min(res, dp[m][i]);
        }
    }

    if(res == LLONG_MAX) cout << -1;
    else cout << res;
    return 0;
}

• Subtask 1: 20 / 20
• Subtask 2: 50 / 50