Submission #1041565

#	Time	Username	Problem	Language	Result	Execution time	Memory
1041565		vjudge1	Ljetopica (COI19_ljetopica)	C++17	8 / 100	1041 ms	600 KiB

ljetopica

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define MOD 1000000007
ll  n ,k , c1 = 0, c2 = 0;
string s;
ll ch(ll u , ll rem , ll c , ll curr){
    if(rem < 0 or (u == n - 1 and (rem > 0 or c < c1 or c > c2))){
        return 0;
    }
    if(u == n - 1){
        return c;
    }
    if(curr){
        if(s[u] == 'L'){
            return (ch(u + 1, rem - 1, c * 2 + 1, 1 - curr) + ch(u + 1, rem, c * 2 + 1, curr)) % MOD;
        }
        else{
            return (ch(u + 1, rem - 1, c * 2, 1 - curr) + ch(u + 1, rem, c * 2, curr)) % MOD;
        }
    }
    else{
        if(s[u] == 'R'){
            return (ch(u + 1, rem - 1, c * 2 + 1, 1 - curr) + ch(u + 1, rem, c * 2 + 1, curr)) % MOD;
        }
        else{
            return (ch(u + 1, rem - 1, c * 2, 1 - curr) + ch(u + 1, rem, c * 2, curr)) % MOD;
        }
    }

}
void solve(){
    cin >> n >> k;
    string a  , b;
    cin >> s >> a >> b;
    for(int i = 0 ;i < a.length(); i ++){
        c1 = ((c1 * 2) + (a[i] - '0')) % MOD;
        c2 = ((c2 * 2) + (b[i] - '0')) % MOD;
    }
    if(c1 == c2){
        c1 = 0 ;
    }
    if(k == 0){
        cout << (c1 + c2) % MOD << '\n';
    }
    else{
        cout << (ch(0 , k, 1 ,0) + ch(0 , k, 1 ,1)) % MOD << '\n';
    }
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    int tests = 1;
    // cin >> tests;
    for (int i = 1; i <= tests; i++){
        solve();
    }
    return 0;
}

Compilation message (stderr)

ljetopica.cpp: In function 'void solve()':
ljetopica.cpp:36:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for(int i = 0 ;i < a.length(); i ++){
      |                    ~~^~~~~~~~~~~~

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