Submission #1118263

#	Time	Username	Problem	Language	Result	Execution time	Memory
1118263		vjudge1	Kangaroo (CEOI16_kangaroo)	C++17	0 / 100	1 ms	348 KiB

kangaroo

/*
#ifndef ONLINE_JUDGE
#include "AkbarKING.h" // aska geldi akbarking.h
#else
#define debug(...)
#define debugArr(...)
#define debugG(...)
#endif
*/
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/hash_policy.hpp>

#define int long long
#define $AzH_TxdmN$ ios_base::sync_with_stdio(0);cin.tie(nullptr);cout.tie(nullptr);
#pragma GCC target("sse,sse2,sse3,ssse3,popcnt,abm,mmx,tune=native")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("no-stack-protector")
#pragma GCC optimize("unroll-loops")
#pragma GCC optimize("fast-math")

#define ep emplace_back
#define pb push_back
#define pii pair<int,int>
#define all(v) v.begin(),v.end()
#define rall(v) v.rbegin(),v.rend()

#define heap pii,vector<pii>,less<pii>
using namespace std;
using namespace __gnu_pbds;

template <typename T>
using __indexed_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
template <typename T>
using __indexed_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;

const int sz = 2e3+9;
const int LOG = 63;
const int MOD = 1e9+7;
const int INF = 1e18;
int dp[sz][sz];

int n,cs,cf;

void solve()
{
    cin>>n>>cs>>cf;
    dp[0][0] = 1;
    int fixed = 0;
    for (int i = 1; i <= n; ++i)
    {
        fixed += (i > cs) + (i > cf);
        for (int j = 1; j <= i; ++j)
        {
            if (i == cs || i == cf)
            {
                dp[i][j] = ((dp[i][j] + dp[i-1][j-1]) % MOD + (dp[i-1][j])) % MOD;
            }
            else
            {
                dp[i][j] = (dp[i][j] + (dp[i-1][j+1]*j)%MOD)%MOD;
                dp[i][j] = (dp[i][j] + (dp[i-1][j-1]*(j-fixed))%MOD)%MOD;
            }
        }
    }
    cout<<dp[n][1]<<'\n';
}

signed main()
{
    $AzH_TxdmN$
    //freopen("kangaroo.in", "r", stdin);
    //freopen("kangaroo.out", "w", stdout);
    int t = 1;
    //cin>>t;
    while (t--)
    {
        solve();
    }
}

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