Submission #558347

#	Time	Username	Problem	Language	Result	Execution time	Memory
558347		Yazan_Alattar	Ljetopica (COI19_ljetopica)	C++14	8 / 100	1 ms	324 KiB

ljetopica

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define aint(x) x.begin(), x.end()
const int M = 3007;
const ll inf = 2e9;
const ll mod = 1e9 + 7;
const double pi = acos(-1);
const double eps = 1e-6;
const int dx[] = {0, -1, 0, 1}, dy[] = {1, 0, -1, 0};
const int block = 320;

string s, a, b;
ll n, k;

ll check(string s){
    ll res = 1;
    int mn = 1, mx = 1;

    for(int i = 0; i < n - 1; ++i){
        if(s[i] == 'L'){
            // bit = 0
            res = (res * 2) % mod;

            if(mx == 1 && a[i + 1] == '1') mx = 0;
            if(mn == 1 && b[i + 1] == '1') mn = 2;
        }
        else{
            // bit = 1
            res = (res * 2 + 1) % mod;

            if(mx == 1 && a[i + 1] == '0') mx = 2;
            if(mn == 1 && b[i + 1] == '0') mn = 0;
        }
    }

    if(mn && mx) return res;
    return 0ll;
}

int main(){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    string S;
    cin >> n >> k >> S >> a >> b;

    ll ans = check(S);

    for(int i = 0; i < n - 1; ++i){
        if(S[i] == 'L') S[i] = 'R';
        else S[i] = 'L';
    }
    ans += check(S);

    cout << ans % mod << endl;
    return 0;
}

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