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답안 #83307

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
83307 2018-11-06T22:11:41 Z fredbr Mate (COCI18_mate) C++17
80 / 100
 2000 ms 42312 KB 
#include <bits/stdc++.h>

using namespace std;

const int maxm = 30;
const int maxn = 2010;

typedef long long ll;

const ll mod = 1000000007;

ll dp[maxm][maxm][maxn];
ll pchoose[maxn][maxn];

ll choose(ll n, ll k)
{
	if (pchoose[n][k] >= 0) return pchoose[n][k];

	return pchoose[n][k] = (choose(n-1, k) + choose(n-1, k-1)) % mod;
}

void init()
{
	memset(pchoose, -1, maxn*maxn*8);
	
	for (int i = 0; i < maxn; i++) {

		pchoose[i][0] = 1;
		pchoose[i][i] = 1;
	}
}

int main()
{	
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	
	string s;
	cin >> s;

	int n = s.size();

	init();

	for (int i = 0; i < n-1; i++) {

		for (int j = i+1; j < n; j++) {

			for (int k = 0; k <= i; k++) {

				dp[s[i]-'a'][s[j]-'a'][k+2] += choose(i, k);
				dp[s[i]-'a'][s[j]-'a'][k+2] %= mod;
			}
		}
	}

	int q;
	cin >> q;

	while (q--) {

		int num;
		char a, b;

		cin >> num >> a >> b;

		cout << dp[a-'a'][b-'a'][num] << "\n";
	}

	return 0;
}

Subtask #1
80.0 / 100.0

# 결과 실행 시간 메모리 Grader output
1 Correct 34 ms 34040 KB Output is correct
2 Correct 32 ms 34040 KB Output is correct
3 Correct 33 ms 34296 KB Output is correct
4 Correct 36 ms 34492 KB Output is correct
5 Correct 72 ms 38160 KB Output is correct
6 Correct 73 ms 39304 KB Output is correct
7 Correct 67 ms 39984 KB Output is correct
8 Correct 61 ms 40520 KB Output is correct
9 Execution timed out 2068 ms 42312 KB Time limit exceeded
10 Execution timed out 2072 ms 42312 KB Time limit exceeded