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답안 #518634

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
518634 2022-01-24T10:25:44 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 mid, l, r;
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 lx, int rx) {
    if(lx == 0) {
        q = g[rx - 1], w = g2[rx - 1];
        return make_pair(q, w);
    }
    q = g[rx - 1] - g[lx - 1]; q %= md; q += md; q %= md;
    q = 1LL * q * taq[lx] % md;
    w = g2[rx - 1] - g2[lx - 1]; w %= md2; w += md2; w %= md2;
    w = 1LL * w * qat[lx] % md2;
    return make_pair(q, w);
}
inline pii hashF(int lx, int rx) {
    if(lx == 0) {
        q = f[rx - 1], w = f2[rx - 1];
        return make_pair(q, w);
    }
    q = f[rx - 1] - f[lx - 1]; q %= md; q += md; q %= md;
    q = 1LL * q * taq[lx] % md;
    w = f2[rx - 1] - f2[lx - 1]; w %= md2; w += md2; w %= md2;
    w = 1LL * w * qat[lx] % md2;
    return make_pair(q, w);
}

inline int bs(int a, int b) {
    l = 0, r = min(n - a, m - b);
    for(int i = 11; i > -1; i--) {
        if(l + (1 << i) > r) continue;
        if(hashG(a, a + l + (1 << i)) == hashF(b, b + l + (1 << i))) l += (1 << i);
    }
    return l;
}
inline int bs2(int a, int b) {
    l = 0, r = min(1LL * a, m - b - sum);
    for(int i = 11; i > -1; i--) {
        if(l + (1 << i) > r) continue;
        if(hashG(a - (l + (1 << i)), a) == hashF(b + sum, b + sum + l + (1 << i))) l += (1 << i);
    }
    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) break;
            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) break;
            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:32:9: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   32 |         if(b & 1) res *= a; res %= d;
      |         ^~
necklace.cpp:32:29: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   32 |         if(b & 1) res *= a; res %= d;
      |                             ^~~

Subtask #1
5.0 / 25.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 304 KB Output is correct
2 Partially correct 1 ms 332 KB Output is partially correct
3 Partially correct 3 ms 332 KB Output is partially correct
4 Partially correct 2 ms 332 KB Output is partially correct
5 Partially correct 1 ms 332 KB Output is partially correct

Subtask #2
4.0 / 20.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 304 KB Output is correct
2 Partially correct 1 ms 332 KB Output is partially correct
3 Partially correct 3 ms 332 KB Output is partially correct
4 Partially correct 2 ms 332 KB Output is partially correct
5 Partially correct 1 ms 332 KB Output is partially correct
6 Partially correct 10 ms 352 KB Output is partially correct
7 Correct 6 ms 332 KB Output is correct
8 Correct 77 ms 340 KB Output is correct
9 Partially correct 34 ms 332 KB Output is partially correct
10 Partially correct 6 ms 332 KB Output is partially correct
11 Partially correct 6 ms 332 KB Output is partially correct
12 Partially correct 46 ms 332 KB Output is partially correct

Subtask #3
0.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 304 KB Output is correct
2 Partially correct 1 ms 332 KB Output is partially correct
3 Partially correct 3 ms 332 KB Output is partially correct
4 Partially correct 2 ms 332 KB Output is partially correct
5 Partially correct 1 ms 332 KB Output is partially correct
6 Partially correct 10 ms 352 KB Output is partially correct
7 Correct 6 ms 332 KB Output is correct
8 Correct 77 ms 340 KB Output is correct
9 Partially correct 34 ms 332 KB Output is partially correct
10 Partially correct 6 ms 332 KB Output is partially correct
11 Partially correct 6 ms 332 KB Output is partially correct
12 Partially correct 46 ms 332 KB Output is partially correct
13 Partially correct 1202 ms 372 KB Output is partially correct
14 Correct 480 ms 384 KB Output is correct
15 Execution timed out 1593 ms 300 KB Time limit exceeded
16 Halted 0 ms 0 KB -