Submission #219382

#	Time	Username	Problem	Language	Result	Execution time	Memory
219382		NONAME	Trener (COCI20_trener)	C++17	110 / 110	95 ms	6520 KiB

trener

#include <bits/stdc++.h>
#include <time.h>
//#include <random>
//#ifndef _LOCAL
//#pragma GCC optimize("-O3")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
//#endif
#define sz(x) int(x.size())
#define in(x) freopen(x, "r", stdin)
#define out(x) freopen(x, "w", stdout)
#define N 2 * 100500
#define oo ll(1e16)
#define pii pair <int, int>
#define pll pair <ll, ll>
#define ft first
#define sd second
#define pb push_back
#define ppb pop_back
#define mp make_pair
#define el '\n'
#define elf endl
#define base ll(1e9 + 7)
#define re return
#define nins 4294967295
using namespace std;
typedef long long ll;
typedef long double ld;

//mt19937 rnd(0);

ll n, m, dp[50][1510], upd[1510];
string s[50][1510];

void solve() {
    cin >> n >> m;
    for (int i = 0; i < n; i++) {
        for (int j = 0; j < m; j++)
            cin >> s[i][j];

        sort(s[i], s[i] + m);
    }

    for (int j = 0; j < m; j++)
        dp[n - 1][j] = 1;

    for (int i = n - 1; i > 0; i--) {
        for (int j = 0; j < m; j++)
            upd[j] = 0;

        for (int j = 0; j < m; j++) {
            string t1 = s[i][j].substr(0, i);
            string t2 = s[i][j].substr(1, i);

            int p1 = lower_bound(s[i - 1], s[i - 1] + m, t1) - s[i - 1];
            int p2 = upper_bound(s[i - 1], s[i - 1] + m, t1) - s[i - 1];

            upd[p1] += dp[i][j];
            upd[p1] %= base;
            upd[p2] -= dp[i][j];
            while (upd[p2] < 0) upd[p2] += base;
            upd[p2] %= base;

            if (t1 == t2) continue;

            p1 = lower_bound(s[i - 1], s[i - 1] + m, t2) - s[i - 1];
            p2 = upper_bound(s[i - 1], s[i - 1] + m, t2) - s[i - 1];

            upd[p1] += dp[i][j];
            upd[p1] %= base;
            upd[p2] -= dp[i][j];
            while (upd[p2] < 0) upd[p2] += base;
            upd[p2] %= base;
        }

        ll cr = 0;
        for (int j = 0; j < m; j++) {
            cr += upd[j];

            while (cr < 0) cr += base;
            cr %= base;

            dp[i - 1][j] += cr;
            dp[i - 1][j] %= base;
        }
    }

    ll rs = 0;
    for (int j = 0; j < m; j++)
        rs += dp[0][j], rs %= base;

    cout << rs;
}

int main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    #ifdef _LOCAL
        in("input.txt");

        int t = 1;
//        cin >> t;
        for (int i = 1; i <= t; i++) {
            cout << "Test #" << i << elf;

            clock_t start_time = clock();

            solve();

            cerr.precision(4); cerr << fixed;
            cerr << elf;
            cerr << "Time :: " << ld(clock() - start_time) / CLOCKS_PER_SEC << elf;

            cout << elf;
        }
    #else
        int t = 1;
//        cin >> t;

        while (t--) {
            solve();
            cout << el;
        }
    #endif
}

• Subtask 1: 22 / 22
• Subtask 2: 33 / 33
• Subtask 3: 55 / 55