답안 #518591

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
518591 2022-01-24T08:41:44 Z K4YAN Necklace (Subtask 1-3) (BOI19_necklace1) C++17
9 / 85
1500 ms 384 KB
//Be Name Khoda

#include<bits/stdc++.h>
#pragma GCC optmize("Ofast,unroll-loops")
#pragma GCC target ("avx2,tune=native")

using namespace std;

#define ll long long
#define ld long double
#define all(x) x.begin(), x.end()
#define pii pair<int, int>
#define pll pair<ll, ll>
#define plll pair<pll, ll>

const int mxn = 3e3 + 16;
const ll md = 1e9 + 7, md2 = 998244353, p1 = 27, p2 = 31;
ll n, m, q, w, t, sum;
int g[mxn], g2[mxn], f[mxn], f2[mxn], taq[mxn], qat[mxn];
string s, h;

void input() {

    cin >> s >> h;

}

inline ll tav(ll a, ll b, ll d) {
    ll res = 1;
    while(b > 0) {
        if(b & 1) res *= a; res %= d;
        a *= a; a %= d; b >>= 1;
    }
    return res;
}

inline void GGL() {
    taq[0] = qat[0] = 1;
    taq[1] = tav(p1, md - 2, md); qat[1] = tav(p2, md2 - 2, md2);
    for(int i = 2; i < mxn; i++) {
        taq[i] = 1LL * taq[i - 1] * taq[1] % md;
        qat[i] = 1LL * qat[i - 1] * qat[1] % md2;
    } return;
}

inline void build_hash() {
    n = int(s.size());
    q = 0, w = 1;
    for(int i = 0; i < n; i++) {
        q = q + (1LL * w * (s[i] - 'a')); q %= md;
        g[i] = q; w *= p1; w %= md;
    } q = 0, w = 1;
    for(int i = 0; i < n; i++) {
        q = q + (1LL * w * (s[i] - 'a')); q %= md2;
        g2[i] = q; w *= p2; w %= md2;
    }
    return;
}
inline void build_hash2() {
    m = int(h.size());
    q = 0, w = 1;
    for(int i = 0; i < m; i++) {
        q = q + (1LL * w * (h[i] - 'a')); q %= md;
        f[i] = q; w *= p1; w %= md;
    } q = 0, w = 1;
    for(int i = 0; i < m; i++) {
        q = q + (1LL * w * (h[i] - 'a')); q %= md2;
        f2[i] = q; w *= p2; w %= md2;
    }
    return;
}

inline pii hashG(int l, int r) {
    if(l == 0) {
        q = g[r - 1], w = g2[r - 1];
        return make_pair(q, w);
    }
    q = g[r - 1] - g[l - 1]; q %= md; q += md; q %= md;
    q = 1LL * q * taq[l] % md;
    w = g2[r - 1] - g2[l - 1]; w %= md2; w += md2; w %= md2;
    w = 1LL * w * qat[l] % md2;
    return make_pair(q, w);
}
inline pii hashF(int l, int r) {
    if(l == 0) {
        q = f[r - 1], w = f2[r - 1];
        return make_pair(q, w);
    }
    q = f[r - 1] - f[l - 1]; q %= md; q += md; q %= md;
    q = 1LL * q * taq[l] % md;
    w = f2[r - 1] - f2[l - 1]; w %= md2; w += md2; w %= md2;
    w = 1LL * w * qat[l] % md2;
    return make_pair(q, w);
}

inline int bs(int a, int b) {
    int mid, l, r;
    l = 1, r = min(n - a, m - b) + 1;
    while(l < r) {
        if(r - l == 1) break;
        mid = (l + r) >> 1;
        if(hashG(a, a + mid) == hashF(b, b + mid)) {
            l = mid;
        } else {
            r = mid;
        }
    }
    return l;
}
inline int bs2(int a, int b) {
    int mid, l, r;
    l = 0, r = min(1LL * a, m - b - sum) + 1;
    while(l < r) {
        if(r - l == 1) break;
        mid = (l + r) >> 1;
        if(hashG(a - mid, a) == hashF(b + sum, b + sum + mid)) {
            l = mid;
        } else {
            r = mid;
        }
    }
    return l;
}

void solve() {

    GGL();
    build_hash(); build_hash2();
    int ans = 0, st1 = -1, st2 = -1;
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            if(m - j < ans) continue;
            if(s[i] != h[j]) continue;
            sum = bs(i, j);
            w = bs2(i, j); sum += w;
            if(sum > ans) {
                st1 = i - w; st2 = j; ans = sum;
            }
        }
    }
    reverse(all(h));
    build_hash2();
    for(int i = 0; i < n; i++) {
        for(int j = 0; j < m; j++) {
            if(m - j < ans) continue;
            if(s[i] != h[j]) continue;
            sum = bs(i, j);
            w = bs2(i, j); sum += w;
            if(sum > ans) {
                st1 = i - w; st2 = m - j - sum; ans = sum;
            }
        }
    }
    cout << ans << "\n";
    cout << st1 << " " << st2 << "\n";
    return;

}

int main() {

    ios::sync_with_stdio(false); cin.tie(NULL);

    input(), solve();

    return 0;

}

Compilation message

necklace.cpp:4: warning: ignoring '#pragma GCC optmize' [-Wunknown-pragmas]
    4 | #pragma GCC optmize("Ofast,unroll-loops")
      | 
necklace.cpp: In function 'long long int tav(long long int, long long int, long long int)':
necklace.cpp:31:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   31 |         if(b & 1) res *= a; res %= d;
      |         ^~
necklace.cpp:31:29: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   31 |         if(b & 1) res *= a; res %= d;
      |                             ^~~
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 332 KB Output is correct
2 Partially correct 1 ms 332 KB Output is partially correct
3 Correct 3 ms 332 KB Output is correct
4 Partially correct 1 ms 332 KB Output is partially correct
5 Correct 1 ms 332 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 332 KB Output is correct
2 Partially correct 1 ms 332 KB Output is partially correct
3 Correct 3 ms 332 KB Output is correct
4 Partially correct 1 ms 332 KB Output is partially correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 9 ms 348 KB Output is correct
7 Partially correct 8 ms 332 KB Output is partially correct
8 Correct 70 ms 332 KB Output is correct
9 Partially correct 32 ms 332 KB Output is partially correct
10 Partially correct 5 ms 332 KB Output is partially correct
11 Partially correct 6 ms 384 KB Output is partially correct
12 Partially correct 42 ms 332 KB Output is partially correct
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 332 KB Output is correct
2 Partially correct 1 ms 332 KB Output is partially correct
3 Correct 3 ms 332 KB Output is correct
4 Partially correct 1 ms 332 KB Output is partially correct
5 Correct 1 ms 332 KB Output is correct
6 Correct 9 ms 348 KB Output is correct
7 Partially correct 8 ms 332 KB Output is partially correct
8 Correct 70 ms 332 KB Output is correct
9 Partially correct 32 ms 332 KB Output is partially correct
10 Partially correct 5 ms 332 KB Output is partially correct
11 Partially correct 6 ms 384 KB Output is partially correct
12 Partially correct 42 ms 332 KB Output is partially correct
13 Partially correct 1194 ms 368 KB Output is partially correct
14 Partially correct 483 ms 376 KB Output is partially correct
15 Execution timed out 1571 ms 336 KB Time limit exceeded
16 Halted 0 ms 0 KB -