Submission #1258508

#	Time	Username	Problem	Language	Result	Execution time	Memory
1258508		nikaa123	Kangaroo (CEOI16_kangaroo)	C++20	6 / 100	2094 ms	324 KiB

kangaroo

#include <bits/stdc++.h>
using namespace std;

// #define int long long
#define eb emplace_back
#define mp make_pair
#define pb push_back
#define pp pop_back
#define endl '\n'
#define ff first
#define ss second
#define stop exit(0)
#define sz(x) (int)x.size()
#define pause system("pause")
#define all(x) (x).begin(), (x).end()
#define deb(x) cout << #x << "-" << x << endl

typedef char chr;
typedef string str;
typedef long long ll;
typedef vector<int> vii;
typedef pair<int, int> pii;

const long long INF = LLONG_MAX;
const int inf = INT_MAX;
const int mod = 998244353;
const int MOD = 1e9 + 7;
const int dx[] = {0, 0, -1, 1};
const int dy[] = {-1, 1, 0, 0};
const double PI = 2 * acos(0.0);

const int N = 2e3 + 5;

int n,cs,cf;
int fix[N];
int ans;

void rec(int rep, bool dir,int last) {
    if (rep != n && fix[cf]) {
        return;
    }
    if (rep == n) {
        if (last == cf) ans++;
        return;
    }
    if (dir) {
        bool ok = 0;
        for (int i = last+1; i <= n; i++) {
            if (!fix[i]) ok = 1;
        }
        if (!ok) {
            return;
        }
        for (int i = last+1; i <= n; i++) {
            if (!fix[i]) {
                fix[i] = 1;
                rec(rep+1,!dir,i);
                fix[i] = 0;
            }
        }
    } else {
        bool ok = 0;
        for (int i = last-1; i >= 1; i--) {
            if (!fix[i]) ok = 1;
        }
        if (!ok) {
            return;
        }
        for (int i = last-1; i >= 1; i--) {
            if (!fix[i]) {
                fix[i] = 1;
                rec(rep+1,!dir,i);
                fix[i] = 0;
            }
        }
    }
    
}

inline void test_case() {

    cin >> n >> cs >> cf;
    fix[cs] = 1;
    rec(1,1,cs);
    for (int i = 1; i <= n; i++) {
        fix[i] = 0;
    }
    fix[cs] = 1;
    rec(1,0,cs);
    cout << ans << endl;

}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);

    int T = 1;
    // cin >> T;
    while (T--) {
        test_case();
    }
    return 0;
}

• Subtask 1: 6 / 6
• Subtask 2: 0 / 30
• Subtask 3: 0 / 15
• Subtask 4: 0 / 49