Submission #81734

#	Time	Username	Problem	Language	Result	Execution time	Memory
81734		Saboon	Kangaroo (CEOI16_kangaroo)	C++14	36 / 100	2064 ms	92204 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];

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;
    for (int i = 3; i <= n; i++) {
        for (int st = 1; st <= i; st ++) {
            for (int en = 1; en <= i; en ++) {
                if (st == en)
                    continue;
                for (int k = st + 1; k <= i; k++) {
                    if (k != en)
                        dp[i][st][en][1] = (dp[i][st][en][1] + dp[i - 1][k - 1][en - (en > st)][0]) % mod;
                }
                for (int k = st - 1; k >= 1; k--) {
                    if (k != en)
                        dp[i][st][en][0] = (dp[i][st][en][0] + dp[i - 1][k][en - (en > st)][1]) % mod;
                }
            }
        }
    }
    cout << (dp[n][s][t][1] + dp[n][s][t][0]) % mod << endl;
}

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