Submission #233331

#	Time	Username	Problem	Language	Result	Execution time	Memory
233331		kartel	Ljetopica (COI19_ljetopica)	C++14	8 / 100	1086 ms	512 KiB

ljetopica

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define in(x) freopen(x, "r", stdin)
#define out(x) freopen(x, "w", stdout)
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("-O3")
#define F first
#define S second
#define pb push_back
#define N +100500
#define M ll(1e9 + 7)
#define sz(x) (int)x.size()
#define re return
#define oo ll(1e18)
#define el '\n'
#define pii pair <int, int>
using namespace std;
//using namespace __gnu_pbds;
//typedef tree <int, null_type, less_equal <int> , rb_tree_tag, tree_order_statistics_node_update> ordered_set;
typedef long long ll;
typedef long double ld;

string s, a, b;
int n, k, i;
ll ans = 0, A, B, cur;

ll sm(ll x, ll y) {return (x + y) % M;}

ll bp(ll x, ll y)
{
    if (y == 0) return 1ll;
    if (y % 2) return (bp(x, y - 1) * x) % M;
    ll a = bp(x, y / 2);
    return (a * a) % M;
}

void dfs(int v, int i, int l, int r, int tl, int tr, vector <int> f)
{
    if (l > tr || r < tl) return;
    if (l == r)
    {
        cur = sm(cur, f[k] * 1ll * (l + bp(2, n - 1) - 1));
        return;
    }

    vector <int> fl, fr;

    fl.resize(27);
    fr.resize(27);

    if (s[i] == 'L')
    {
        for (int j = 0; j <= k; j++)
        {
            fl[j] = sm(fl[j], f[j]);
            fr[j + 1] = sm(fr[j + 1], f[j]);
        }
    }
    else
    {
        for (int j = 0; j <= k; j++)
        {
            fl[j + 1] = sm(fl[j + 1], f[j]);
            fr[j] = sm(fr[j], f[j]);
        }
    }

    int md = (l + r) >> 1;
    dfs(v * 2, i + 1, l, md, tl, tr, fl);
    dfs(v * 2 + 1, i + 1, md + 1, r, tl, tr, fr);
}

ll calc(int revers)
{
    if (revers)
    {
        for (i = 0; i < n; i++)
        {
            if (s[i] == 'L') s[i] = 'R';
                        else s[i] = 'L';
        }
    }

    A = 0;
    for (i = 0; i < n; i++)
        if (a[i] == '1') A += bp(2, i);

    B = -0;
    for (i = 0; i < n; i++)
        if (b[i] == '1') B += bp(2, i);

    A -= bp(2, n - 1);
    B -= bp(2, n - 1);
    A++;
    B++;

    vector <int> f;
    f.resize(27);

    cur = 0;

    f[0] = 1;

    dfs(1, 0, 1, bp(2, n - 1), A, B, f);

    return cur;
}

int main()
{
    srand(time(0));
    ios_base::sync_with_stdio(0);
    iostream::sync_with_stdio(0);
    ios::sync_with_stdio(0);
    cin.tie(NULL);
    cout.tie(NULL);

//    in("input.txt");
//    out("output.txt");

    cin >> n >> k;
    cin >> s;
    cin >> a;
    cin >> b;
    reverse(a.begin(), a.end());
    reverse(b.begin(), b.end());

    if (k == 0)
    {
        bitset <1005> bt;
        for (i = 0; i <= n; i++) bt[i] = 0;
        bt[0] = 1;
        i = 0;
        while (i < n - 1)
        {
            if (s[i] == 'L')
            {
                bitset <1005> nw;
                for (int i = 1; i <= n; i++) nw[i] = bt[i - 1];
                bt = nw;
            }
            else
            {
                bitset <1005> nw;
                nw[0] = 1;
                for (int i = 1; i <= n; i++) nw[i] = bt[i - 1];
                bt = nw;
            }
            i++;
        }



        i = n - 1;
        while (i >= 0 && bt[i] == a[i] - '0') i--;
//        cerr << i << el;
        if (i < 0 || a[i] == '0')
        {
            i = n - 1;
            while (i >= 0 && bt[i] == b[i] - '0') i--;
            if (i < 0 || b[i] == '1')
            {
                i = 0;
                for (i = 0; i < n; i++)
                {
                    if (bt[i]) ans = sm(ans, bp(2, i));
                }
            }
        }
        for (i = 0; i <= n; i++) bt[i] = 0;
        bt[0] = 1;
        i = 0;
        while (i < n - 1)
        {
            if (s[i] == 'R')
            {
                bitset <1005> nw;
                for (int i = 1; i <= n; i++) nw[i] = bt[i - 1];
                bt = nw;
            }
            else
            {
                bitset <1005> nw;
                nw[0] = 1;
                for (int i = 1; i <= n; i++) nw[i] = bt[i - 1];
                bt = nw;
            }
            i++;
        }


//        for (int i = 0; i < n; i++) cout << bt[i];
//        cout << el;
//        for (int i = 0; i < n; i++) cout << b[i];
//        cout << el;

//        cout << ans << el;

        i = n - 1;
        while (i >= 0 && bt[i] == a[i] - '0') i--;
        if (i < 0 || a[i] == '0')
        {
            i = n - 1;
            while (i >= 0 && bt[i] == b[i] - '0') i--;
            if (i < 0 || b[i] == '1')
            {
                i = 0;
                for (i = 0; i < n; i++)
                {
                    if (bt[i]) ans = sm(ans, bp(2, i));
                }
            }
        }
    }
    else ans = sm(calc(1), calc(0));
    cout << ans % M;
}

• Subtask 1: 8 / 8
• Subtask 2: 0 / 14
• Subtask 3: 0 / 17
• Subtask 4: 0 / 61