Submission #1243418

#	Time	Username	Problem	Language	Result	Execution time	Memory
1243418		chr34	Round words (IZhO13_rowords)	C++20	40 / 100	2096 ms	448 KiB

rowords

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define endl "\n"
#define dbg(x) cout << #x << " = " << (x) << endl;
const int INF = 1e18;
const int MAXN = 1e6 + 10;
const int MOD = 1e9 + 7;

int lcs(const string& a, const string& b) {
    int n = a.size(), m = b.size();
    vector<vector<int>> dp(2, vector<int>(m + 1, 0));
    for (int i = 1; i <= n; ++i) {
        int cur = i % 2, prev = 1 - cur;
        for (int j = 1; j <= m; ++j) {
            if (a[i - 1] == b[j - 1])
                dp[cur][j] = dp[prev][j - 1] + 1;
            else
                dp[cur][j] = max(dp[prev][j], dp[cur][j - 1]);
        }
    }
    return dp[n % 2][m];
}

int32_t main(){
	ios::sync_with_stdio(false);
	cin.tie(nullptr);
	//freopen("input.in", "r", stdin);
	//freopen("input.out", "w", stdout);    
	string s1, s2;
    cin >> s1 >> s2;

    int maxLCS = 0;
    string s1r = s1;
    reverse(s1r.begin(), s1r.end());

    string s2r = s2;
    reverse(s2r.begin(), s2r.end());

    string s2_doubled = s2 + s2;
    string s2r_doubled = s2r + s2r;
    int len = s2.size();

    for (int i = 0; i < len; ++i) {
        string rot_s2 = s2_doubled.substr(i, len);
        string rot_s2r = s2r_doubled.substr(i, len);
        maxLCS = max(maxLCS, lcs(s1, rot_s2));
        maxLCS = max(maxLCS, lcs(s1r, rot_s2));
        maxLCS = max(maxLCS, lcs(s1, rot_s2r));
        maxLCS = max(maxLCS, lcs(s1r, rot_s2r));
    }

    cout << maxLCS << endl;  
    return 0;
}

• Subtask 1: 40 / 100