Submission #865758

#	Time	Username	Problem	Language	Result	Execution time	Memory
865758		hafo	Necklace (Subtask 4) (BOI19_necklace4)	C++14	15 / 15	336 ms	856 KiB

necklace

#include <bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define pb push_back
#define pa pair<int, int>
#define pall pair<ll, int>
#define fi first
#define se second
#define TASK "test"
#define Size(x) (int) x.size()
#define all(x) x.begin(), x.end()
using namespace std;

template<typename T1, typename T2> bool mini (T1 &a, T2 b) {if(a > b) a = b; else return 0; return 1;}
template<typename T1, typename T2> bool maxi (T1 &a, T2 b) {if(a < b) a = b; else return 0; return 1;}

const int MOD = 1e9 + 7;
const int LOG = 20;
const int maxn = 6e3 + 7;
const ll oo = 1e18 + 69;

string a[2];
int kmp[2][maxn], n, m;

void calc(int id, string s, string t) {
    s = s + '.' + t;
    kmp[id][0] = 0;
    int j = 0;
    for(int i = 1; i < Size(s); i++) {
        while(j > 0 && s[i] != s[j]) j = kmp[id][j - 1];
        j += (s[i] == s[j]);
        kmp[id][i] = j;
    }
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    // freopen(TASK".inp", "r", stdin);
    // freopen(TASK".out", "w", stdout);

    cin>>a[0]>>a[1];
    n = Size(a[0]);
    m = Size(a[1]);

    int ans = 0, x = 0, y = 0;
    for(int t = 0; t < 2; t++) {
        for(int i = 0; i < n - 1; i++) {
            calc(1, a[0].substr(i + 1, n - i - 1), a[1]);
            string st = a[0].substr(0, i + 1);
            reverse(all(st));
            reverse(all(a[1]));
            calc(0, st, a[1]);
            reverse(all(a[1]));

            for(int j = 0; j < m - 1; j++) {
                if(maxi(ans, kmp[1][j + n - i] + kmp[0][m - j + i])) {
                    x = (t == 0 ? i - kmp[0][m - j + i] + 1:n - i - 1 - kmp[1][j + n - i]);
                    y = j - kmp[1][j + n - i] + 1;
                }
            }
        }

        reverse(all(a[0]));
    }
    cout<<ans<<"\n";
    cout<<x<<" "<<y<<"\n";
    return 0;
}

• Subtask 1: 15 / 15