Submission #870068

#	Time	Username	Problem	Language	Result	Execution time	Memory
870068		Pichon5	Kangaroo (CEOI16_kangaroo)	C++17	0 / 100	1 ms	344 KiB

kangaroo

#include <bits/stdc++.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <cmath>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <sstream>
#define fvoices ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
#define vi vector<int>
#define sz(x) (int)x.size()
#define all(x) x.begin(),x.end()
#define S second
#define F first
#define pb push_back
#define rep(i,a,b) for(int i=a;i<b;i++)
#define pii pair<int,int>
#define vii vector<pii>
#define endl '\n'
#define int long long
#define ll long long
using namespace std;
const int tam=2005;
int dp[tam][tam];
const int MOD=1e9 +7;
int add(int a, int b){
	return (a%MOD+b%MOD)%MOD;
}
int mul(int a, int b){
	return (a%MOD*b%MOD)%MOD;
}

signed main(){
	int n,a,b;
	cin>>n>>a>>b;
	// inicio en a termino en b
	dp[1][1]=1;// [elementos][chunks]
	for(int i=2;i<=n;i++){
		for(int l=1;l<=n;l++){
			if(i==a or i==b){
				dp[i][l]=add(dp[i-1][l-1],dp[i-1][l]);
				continue;
			}
			// crear un nuevo chunk
			int espacios=l - (i>a) - (i>b);
			if(espacios<0)espacios=0;
			dp[i][l]=mul(espacios,dp[i-1][l]);
			// unir chunks
			dp[i][l]=add(dp[i][l],mul(l,dp[i-1][l+1]));
		}
	}

	cout<<dp[n][1]<<endl;

    return 0;
}

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