Submission #81736

#	Time	Username	Problem	Language	Result	Execution time	Memory
81736		Saboon	Kangaroo (CEOI16_kangaroo)	C++14	51 / 100	693 ms	525312 KiB

kangaroo

#include <iostream>
#include <sstream>
#include <queue>
#include <stack>
#include <vector>
#include <cstring>
#include <cmath>
#include <map>
#include <unordered_map>
#include <set>
#include <algorithm>
#include <iomanip>
#define F first
#define S second
#define PB push_back
#define PF push_front
#define MP make_pair
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
const int maxn = 210 + 37;
const int mod = 1e9 + 7;

ll dp[maxn][maxn][maxn][3], par[maxn][maxn][maxn][3];

int main() {
    ios_base::sync_with_stdio(false);
    int n, s, t;
    cin >> n >> s >> t;
    dp[2][1][2][1] = 1;
    dp[2][2][1][0] = 1;
    par[2][1][2][1] = 1;
    par[2][2][2][1] = 1;
    par[2][2][1][0] = 1;
    for (int i = 3; i <= n; i++) {
        for (int st = 1; st <= i; st ++) {
            for (int en = 1; en <= i; en ++) {
                if (st != en) {
                    if (en > st) {
                        dp[i][st][en][1] = (dp[i][st][en][1] + par[i - 1][i - 1][en - 1][0] - par[i - 1][st - 1][en - 1][0] + mod + mod) % mod;
                        dp[i][st][en][0] = (dp[i][st][en][0] + par[i - 1][st - 1][en - 1][1]) % mod;
                    }
                    else {
                        dp[i][st][en][1] = (dp[i][st][en][1] + par[i - 1][i - 1][en][0] - par[i - 1][st - 1][en][0] + mod + mod) % mod;
                        dp[i][st][en][0] = (dp[i][st][en][0] + par[i - 1][st - 1][en][1] + mod) % mod;
                    }
//                  cout << i << " " << st << " " << en << " right " << dp[i][st][en][1] << endl;
//                  cout << i << " " << st << " " << en << " left " << dp[i][st][en][0] << endl;
                }
                par[i][st][en][1] = (par[i][st - 1][en][1] + dp[i][st][en][1]) % mod;
                par[i][st][en][0] = (par[i][st - 1][en][0] + dp[i][st][en][0]) % mod;
            }
        }
    }
    cout << (dp[n][s][t][1] + dp[n][s][t][0]) % mod << endl;
}

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