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답안 #194263

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
194263 2020-01-16T01:24:26 Z rama_pang 캥거루 (CEOI16_kangaroo) C++14
100 / 100
 232 ms 126428 KB 
#include <bits/stdc++.h>
using namespace std;
using lint = long long;
const lint MOD = 1e9 + 7;

int N, S, T;
lint memo[2005][2005][2][2];

lint dp(int n, int comp, int lend, int rend) {
    if (comp < 0) { 
        return 0; 
    }
    if (n == N - 1) { 
        return comp == 0 ? 1 : 0; // use last piece to merge S and T component
    }

    lint &res = memo[n][comp][lend][rend];
    if (res != -1) {
        return res;
    }
    
    res = 0;

    if (n == S) {
        res += dp(n + 1, comp, 1, rend); // make new component
        res += dp(n + 1, comp - 1, 1, rend) * comp; // connect a component to left end
    } else if (n == T) {
        res += dp(n + 1, comp, lend, 1); // make new component
        res += dp(n + 1, comp - 1, lend, 1) * comp; // connect a component to right end
    } else {
        res += dp(n + 1, comp + 1, lend, rend); // add a new component
        res += dp(n + 1, comp - 1, lend, rend) * comp * (comp - 1); // merge two components
        res += dp(n + 1, comp - 1, lend, rend) * comp * lend; // connect component to left end
        res += dp(n + 1, comp - 1, lend, rend) * comp * rend; // connect component to right end
    }

    res %= MOD;
    return res;
}

int main() {
    memset(memo, -1, sizeof(memo));
    cin >> N >> S >> T;
    S--, T--;
    cout << dp(0, 0, 0, 0) << "\n";
    return 0;
}

Subtask #1
6.0 / 6.0

# 결과 실행 시간 메모리 Grader output
1 Correct 107 ms 126352 KB Output is correct
2 Correct 115 ms 126156 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 107 ms 126352 KB Output is correct
2 Correct 115 ms 126156 KB Output is correct
3 Correct 118 ms 126272 KB Output is correct
4 Correct 106 ms 126176 KB Output is correct
5 Correct 106 ms 126200 KB Output is correct
6 Correct 106 ms 126136 KB Output is correct
7 Correct 107 ms 126172 KB Output is correct
8 Correct 106 ms 126120 KB Output is correct
9 Correct 106 ms 126120 KB Output is correct
10 Correct 108 ms 126132 KB Output is correct
11 Correct 106 ms 126200 KB Output is correct

Subtask #3
15.0 / 15.0

# 결과 실행 시간 메모리 Grader output
1 Correct 107 ms 126352 KB Output is correct
2 Correct 115 ms 126156 KB Output is correct
3 Correct 118 ms 126272 KB Output is correct
4 Correct 106 ms 126176 KB Output is correct
5 Correct 106 ms 126200 KB Output is correct
6 Correct 106 ms 126136 KB Output is correct
7 Correct 107 ms 126172 KB Output is correct
8 Correct 106 ms 126120 KB Output is correct
9 Correct 106 ms 126120 KB Output is correct
10 Correct 108 ms 126132 KB Output is correct
11 Correct 106 ms 126200 KB Output is correct
12 Correct 107 ms 126200 KB Output is correct
13 Correct 111 ms 126200 KB Output is correct
14 Correct 106 ms 126284 KB Output is correct
15 Correct 107 ms 126224 KB Output is correct
16 Correct 102 ms 126200 KB Output is correct
17 Correct 107 ms 126232 KB Output is correct
18 Correct 107 ms 126184 KB Output is correct
19 Correct 108 ms 126200 KB Output is correct
20 Correct 107 ms 126148 KB Output is correct

Subtask #4
49.0 / 49.0

# 결과 실행 시간 메모리 Grader output
1 Correct 107 ms 126352 KB Output is correct
2 Correct 115 ms 126156 KB Output is correct
3 Correct 118 ms 126272 KB Output is correct
4 Correct 106 ms 126176 KB Output is correct
5 Correct 106 ms 126200 KB Output is correct
6 Correct 106 ms 126136 KB Output is correct
7 Correct 107 ms 126172 KB Output is correct
8 Correct 106 ms 126120 KB Output is correct
9 Correct 106 ms 126120 KB Output is correct
10 Correct 108 ms 126132 KB Output is correct
11 Correct 106 ms 126200 KB Output is correct
12 Correct 107 ms 126200 KB Output is correct
13 Correct 111 ms 126200 KB Output is correct
14 Correct 106 ms 126284 KB Output is correct
15 Correct 107 ms 126224 KB Output is correct
16 Correct 102 ms 126200 KB Output is correct
17 Correct 107 ms 126232 KB Output is correct
18 Correct 107 ms 126184 KB Output is correct
19 Correct 108 ms 126200 KB Output is correct
20 Correct 107 ms 126148 KB Output is correct
21 Correct 115 ms 126276 KB Output is correct
22 Correct 142 ms 126200 KB Output is correct
23 Correct 119 ms 126212 KB Output is correct
24 Correct 219 ms 126328 KB Output is correct
25 Correct 213 ms 126428 KB Output is correct
26 Correct 218 ms 126352 KB Output is correct
27 Correct 232 ms 126368 KB Output is correct
28 Correct 172 ms 126360 KB Output is correct