Submission #1065536

#	Time	Username	Problem	Language	Result	Execution time	Memory
1065536		Malix	Kangaroo (CEOI16_kangaroo)	C++14	0 / 100	0 ms	348 KiB

kangaroo

#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef vector<int> vi;
typedef vector<vi> vii;
typedef pair<int,int> pi;
typedef vector<pi> pii;
typedef tuple<int,int,int> tii;
typedef vector<ll> li;
typedef vector<li> lii;
 
#define REP(i,a,b) for(int i=a;i<b;i++)
#define F first
#define S second
#define PB push_back
#define MP make_pair
#define LSOne(s) ((s)&(-s))
 
ll INF=1000000000000000010;
int inf=1e9+10;
ll M=1e9+7;

int main() {   
    int n,x,y;cin>>n>>x>>y;
    x--;y--;
    vector<vector<ll>> dp(n,vector<ll>(n+1,0));
    dp[0][1]=1;
    REP(i,1,n){
        if(i==x||i==y)REP(j,1,n+1)dp[i][j]=(dp[i-1][j]+dp[i-1][j-1])%M;
        else REP(j,1,n)dp[i][j]=(dp[i-1][j+1]*j+dp[i-1][j-1]*(j-(i<x)-(i<y)))%M;
    }
    cout<<dp[n-1][1];
}

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