Submission #933648

#	Time	Username	Problem	Language	Result	Execution time	Memory
933648		mgch	Round words (IZhO13_rowords)	C++14	48 / 100	2019 ms	17492 KiB

rowords

#include <bits/stdc++.h>

using namespace std;

/** so there is complicated algo based on some research let's get it later
 * 
 * 
 *  you have to get that |lcs(a, b) - lcs(a, b[1..n-1] + b[0])| <= 2
 *  so if you have ans >= lcs(a, b) + 2 then ... push it
 * */

const int N = 2024;

int dp[N][N], gr[N], n, m;
string s[N], t[N];

int lcs(const string &a, const string &b) {
    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < m; ++j) {
            dp[i + 1][j + 1] = max(dp[i + 1][j], dp[i][j + 1]);
            if (a[i] == b[j]) {
                dp[i + 1][j + 1] = max(dp[i + 1][j + 1], dp[i][j] + 1);
            }
        }
    }
    return dp[n][m];
}


int main() {
//  freopen("rowords.in", "r", stdin); freopen("rowords.out", "w", stdout);
    string a, b;
    getline(cin, a);
    getline(cin, b);
    if (a.length() < b.length()) {
       swap(a, b);
    }
    n = a.length();
    m = b.length();
    int ans = 0;
    for (int i = 0; i < n; ++i) {
        s[i] = a.substr(i) + a.substr(0, i);
    }
    vector <pair <int, int> > all;
    for (int i = 0; i < m; ++i) {
        t[i] = b.substr(i) + b.substr(0, i);
        for (int j = 0; j < m; ++j) {
            if (gr[i] < n && t[i][j] == a[gr[i]]) {
                ++gr[i];
            }
        }
        all.push_back(make_pair(-gr[i], i));
    }
    sort(all.rbegin(), all.rend());
    for (int i = 0; i < 1; ++i) {
        for (int jj = 0; jj < m && jj < ((int)5e8) / (n * m); ++jj) {
            int j = all[jj].second;
            ans = max(ans, lcs(s[i], t[j]));
        }
    }
    cout << ans << '\n';
    return 0;
}

• Subtask 1: 48 / 100