Submission #1109371

#	Time	Username	Problem	Language	Result	Execution time	Memory
1109371		ASN49K	Kangaroo (CEOI16_kangaroo)	C++14	36 / 100	74 ms	15824 KiB

kangaroo

#include <bits/stdc++.h>
#include <sys/time.h>
using namespace std;
using i64=long long;
#define UNUSED -1
#define all(x) x.begin(),x.end()
#define pb push_back
const int mod=1e9+7,inf=1e9+1;
const i64 INF=1e18;
int add(int x,int y)
{
    return (x+y)%mod;
}
void add_self(int& x,int y)
{
    x+=y;
    if(x>=mod)
    {
        x-=mod;
    }
}
int prod(int x,int y)
{
    return (1LL*x*y)%mod;
}
mt19937 rng(69);

const int N=100;
int dp[N][N][N][2];

int signatura(int x)
{
    if(x>=0)
    {
        return 1;
    }
    return 0;
}
int main()
{
    int n,start,finish;
    cin>>n>>start>>finish;
    dp[0][0][0][0]=dp[0][0][0][1]=1;
    for(int step=1;step<n;step++)
    {
        for(int poz_start=0;poz_start<step;poz_start++)
        {
            for(int now=0;now<=step;now++)
            {
                int sol[2]={0,0};
                for(int middle=0;middle<step;middle++)
                {
                    add_self(sol[signatura(middle-now)] , dp[step-1][poz_start][middle][signatura(middle-now)^1]);
                }
                dp[step][poz_start+(now<=poz_start)][now][0]=sol[0];
                dp[step][poz_start+(now<=poz_start)][now][1]=sol[1];
            }
        }
    }
    cout<<add(dp[n-1][start-1][finish-1][0],dp[n-1][start-1][finish-1][1]);
}

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