Submission #1173320

#	Time	Username	Problem	Language	Result	Execution time	Memory
1173320		Minbaev	Kangaroo (CEOI16_kangaroo)	C++20	6 / 100	2095 ms	328 KiB

kangaroo

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>

#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast,unroll-loops")

using namespace std;
using namespace __gnu_pbds;

#define pb 		push_back
#define all(x)	x.begin(),x.end()
#define int 	long long
#define ar 		array

template<class T>bool umax(T &a,T b){if(a<b){a=b;return true;}return false;}
template<class T>bool umin(T &a,T b){if(b<a){a=b;return true;}return false;}

template<class T> using ste = tree<T, null_type, less_equal<T>,
rb_tree_tag, tree_order_statistics_node_update>;

namespace FAST {
    template<typename T, typename F>
    istream &operator>>(istream &cin, pair<T, F> &p) {
        cin >> p.first >> p.second;
        return cin;
    }

    template<typename T, typename F>
    ostream &operator<<(ostream &cout, pair<T, F> &p) {
        cout << p.first << ' ' << p.second;
        return cout;
    }

    template<typename T>
    istream &operator>>(istream &cin, vector<T> &a) {
    for (T &i: a) cin >> i;
        return cin;
    }

    template<typename T>
    ostream &operator<<(ostream &cout, vector<T> &a) {
        for (T i: a) cout << i << ' ';
        return cout;
    }

    template<typename T>
    istream &operator>>(istream &cin, deque<T> &a) {
        for (T &i: a) cin >> i;
        return cin;
    }

    template<typename T>
    ostream &operator<<(ostream &cout, deque<T> &a) {
        for (T i: a) cout << i << ' ';
        return cout;
    }
}
using namespace FAST;

const int inf = 3e18 + 7;
const int mod = 1e9 + 7;
const int N = 5e5 + 5;
const int md = 998244353;

int binpow(int a, int b, int m){
	if(b == 0)return 1;
	if(b % 2 == 0){
		int c = binpow(a,b/2,m);
		return (c*c)%m;
	}
	return (binpow(a,b-1,m)*a)%m;
}

int divi(int a, int b, int m){
	return (a*(binpow(b,m-2, m)))%m;
}

int n,m,k,q;
vector<int>vis(100);
int res = 0;

void dfs(int x, int dir, int op){
	if(op == n){
		if(x == k)
			res += 1;
		return;
	}
	if(dir == 0){
		for(int i = x-1;i>=1;i--){
			if(vis[i])continue;
			vis[i] = 1;
			dfs(i, 1, op+1);
			vis[i] = 0;
		}
	}
	if(dir == 1){
		for(int i = x+1;i<=n;i++){
			if(vis[i])continue;
			vis[i] = 1;
			dfs(i, 0, op+1);
			vis[i] = 0;
		}
	}
}

void solve(){
	
	cin >> n >> m >> k;
	
	vis[m] = 1;
	dfs(m, 0, 1);
	dfs(m, 1, 1);
	
	cout << res << "\n";
	
	
	
	
	
	
	
	
	
}
/*

*/
 signed main()
{
//	freopen("seq.in", "r", stdin);
//  freopen("seq.out", "w", stdout);
	ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
	int tt=1;//cin>>tt;
	while(tt--)solve();

}

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