Submission #1061827

#	Time	Username	Problem	Language	Result	Execution time	Memory
1061827		sleepntsheep	Copy and Paste 3 (JOI22_copypaste3)	C++17	100 / 100	1469 ms	76484 KiB

copypaste3

#pragma GCC optimize("O3,unroll-loops")

#include <deque>
#include <string>
#include <iostream>
#include <map>
#include <cstring>
#include <vector>
#include <algorithm>
using namespace std;
using ll = long long;
template <typename T>
using ve = vector<T>;
template <typename T>
using bs = basic_string<T>;

const int N = 2505;
const ll B = 137, M = 1000000007,
      B2 = 141, M2 = 1000000009;

int n, nxt[N][N];
ll dp[N][N], a, b, c;
char s[N];

ll hs[N], bp[N], ibp[N], bp2[N], ibp2[N], hs2[N], x;

ll bpow(ll a, ll b, ll m) {
    if (!b) return 1;
    ll r { bpow(a, b / 2, m) };
    if (b & 1) return r * r % m * a % m;
    return r * r % m;
}

void do_hash() {
    bp[0] = ibp[0] = bp2[0] = ibp2[0] = 1;
    for (int i = 1; i <= n; ++i) bp[i] = bp[i - 1] * B % M, ibp[i] = bpow(bp[i], M - 2, M);
    for (int i = 1; i <= n; ++i) hs[i] = bp[i] * (s[i] - 'a' + 1) % M, hs[i] = (hs[i] + hs[i - 1]) % M;

    for (int i = 1; i <= n; ++i) bp2[i] = bp2[i - 1] * B2 % M2, ibp2[i] = bpow(bp2[i], M2 - 2, M2);
    for (int i = 1; i <= n; ++i) hs2[i] = bp2[i] * (s[i] - 'a' + 1) % M2, hs2[i] = (hs2[i] + hs2[i - 1]) % M2;
}

inline ll get_hash(int l, int r) {
    return (ibp[l] * (hs[r] - hs[l - 1] + M) % M) * (ibp2[l] * (hs2[r] - hs2[l - 1] + M2) % M2);
}

ve<bs<int>> oo;

void init() {
    do_hash();
    memset(dp, 63, sizeof dp);

    for (int i = 1; i <= n; ++i)
        dp[i][i] = a;

    for (int l = 1; l <= n; ++l) {
        map<ll, deque<int>> w;
        for (int i = n - l + 1, j = n; i >= 1; --i, --j) {
            x = get_hash(i, j);
            auto it = lower_bound(w[x].begin(), w[x].end(), i + l);
            if (it == w[x].end()) nxt[i][j] = -1;
            else nxt[i][j] = *it;
            w[x].push_front(i);
        }
    }
}

int main() {
    scanf("%d%s%lld%lld%lld", &n, s + 1, &a, &b, &c);

    init();

    for (int l = 1; l <= n; ++l) {
        for (int i = 1, j = l; j <= n; ++i, ++j) {
            dp[i][j] = min(dp[i][j], dp[i + 1][j] + a);
            dp[i][j] = min(dp[i][j], dp[i][j - 1] + a);
            for (int at = i, cnt = 1; ~at; ++cnt, at = nxt[at][at + l - 1]) {
                int jj = at + l - 1;
                dp[i][jj] = min(dp[i][jj], dp[i][j] + b + cnt * c + (jj - i + 1 - cnt * l) * a);
            }
        }
    }

    printf("%lld", dp[1][n]);
}

Compilation message (stderr)

copypaste3.cpp: In function 'int main()':
copypaste3.cpp:69:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   69 |     scanf("%d%s%lld%lld%lld", &n, s + 1, &a, &b, &c);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 1 / 1
• Subtask 2: 5 / 5
• Subtask 3: 14 / 14
• Subtask 4: 10 / 10
• Subtask 5: 32 / 32
• Subtask 6: 38 / 38