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답안 #940296

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
940296 2024-03-07T07:40:36 Z parlimoos 캥거루 (CEOI16_kangaroo) C++14
100 / 100
 132 ms 39252 KB 
//Be Name KHODA
#pragma GCC optimize("Ofast")
#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
#define pb push_back
#define pp pop_back
#define lb lower_bound
#define ub upper_bound
#define cl clear
#define bg begin
#define arr(x) array<int , x>
#define endl '\n'

const int MOD = int(1e9) + 7;

int n , s , t;
int dp[2001][2001][4];
vector<int> a;

void Add(int &a , int b){
    a += b;
    if(a > MOD) a -= MOD;
    if(a < 0) a += MOD;
}
int Mul(int a , int b){
    return (1ll * a * b) % MOD;
}
int Pow(int a , int b){
    int res = 1;
    while(b){
        if((b & 1)) res = Mul(res , a);
        a = Mul(a , a) , b >>= 1;
    }
    return res;
}
int f(){
    dp[0][0][3] = 1;
    for(int i = 1 ; i <= n ; i++) if(i != s and i != t) a.pb(i);
    for(int i = 0 ; i < n - 2 ; i++){
        for(int c = 0 ; c <= i ; c++){
            for(int md = 0 ; md < 4 ; md++){
                int d = __builtin_popcount(md) - 1;
                Add(dp[i + 1][c + 1][md] , Mul(c + d , dp[i][c][md]));
                if(c > 1) Add(dp[i + 1][c - 1][md] , Mul(c - 1 , dp[i][c][md]));
                if((md & 1)){
                    if(a[i] < s) Add(dp[i + 1][c + 1][md ^ 1] , dp[i][c][md]);
                    if(a[i] > s and c > 0) Add(dp[i + 1][c][md ^ 1] , dp[i][c][md]);
                }
                if(((md >> 1) & 1)){
                    if(a[i] < t) Add(dp[i + 1][c + 1][md ^ 2] , dp[i][c][md]);
                    if(a[i] > t and c > 0) Add(dp[i + 1][c][md ^ 2] , dp[i][c][md]);
                }
            }
        }
    }
    return dp[n - 2][1][0];
}

int main(){
    cin >> n >> s >> t;
    if(s > t) swap(s , t);
    if(n == 2) cout << 1;
    else if(n == 3){
        if((s == 1 and t == 3) or (s == 1 and t == 3)) cout << 0;
        else cout << 1;
    }else cout << f();
}

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 440 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 0 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 0 ms 604 KB Output is correct
10 Correct 1 ms 600 KB Output is correct
11 Correct 0 ms 604 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 440 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 0 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 0 ms 604 KB Output is correct
10 Correct 1 ms 600 KB Output is correct
11 Correct 0 ms 604 KB Output is correct
12 Correct 2 ms 1372 KB Output is correct
13 Correct 2 ms 1372 KB Output is correct
14 Correct 1 ms 1372 KB Output is correct
15 Correct 2 ms 1496 KB Output is correct
16 Correct 2 ms 1372 KB Output is correct
17 Correct 2 ms 1372 KB Output is correct
18 Correct 2 ms 1372 KB Output is correct
19 Correct 2 ms 1372 KB Output is correct
20 Correct 2 ms 1372 KB Output is correct

Subtask #4
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 344 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 440 KB Output is correct
5 Correct 1 ms 604 KB Output is correct
6 Correct 0 ms 604 KB Output is correct
7 Correct 1 ms 604 KB Output is correct
8 Correct 1 ms 604 KB Output is correct
9 Correct 0 ms 604 KB Output is correct
10 Correct 1 ms 600 KB Output is correct
11 Correct 0 ms 604 KB Output is correct
12 Correct 2 ms 1372 KB Output is correct
13 Correct 2 ms 1372 KB Output is correct
14 Correct 1 ms 1372 KB Output is correct
15 Correct 2 ms 1496 KB Output is correct
16 Correct 2 ms 1372 KB Output is correct
17 Correct 2 ms 1372 KB Output is correct
18 Correct 2 ms 1372 KB Output is correct
19 Correct 2 ms 1372 KB Output is correct
20 Correct 2 ms 1372 KB Output is correct
21 Correct 14 ms 6492 KB Output is correct
22 Correct 16 ms 7004 KB Output is correct
23 Correct 18 ms 7704 KB Output is correct
24 Correct 119 ms 39220 KB Output is correct
25 Correct 126 ms 39108 KB Output is correct
26 Correct 127 ms 39252 KB Output is correct
27 Correct 132 ms 38736 KB Output is correct
28 Correct 74 ms 23892 KB Output is correct