#include <bits/stdc++.h>
using namespace std;
vector <int> arr;
int n;
int dp[2001][26][26] = {};
const int MOD = 1e9 + 7;
int ncr[2001][2001];
int main () {
ios::sync_with_stdio(false);
cin.tie(0);
string s;
cin >> s;
n = s.length();
for (int i = 0; i <= n; i++) {
for (int j = 0; j <= n; j++) {
if (j == 0 || j == i) {
ncr[i][j] = 1;
} else if (i < j) {
ncr[i][j] = 0;
} else {
ncr[i][j] = ncr[i - 1][j] + ncr[i - 1][j - 1];
if (ncr[i][j] >= MOD) ncr[i][j] -= MOD;
}
}
}
arr.push_back(8);
for (auto i : s) arr.push_back(i - 'a');
for (int i = 1; i <= n - 1; i++) {
for (int j = i + 1; j <= n; j++) {
for (int k = 2; k <= i + 1; k++) {
dp[k][arr[i]][arr[j]] += ncr[i - 1][i + 1 - k];
if (dp[k][arr[i]][arr[j]] >= MOD) dp[k][arr[i]][arr[j]] -= MOD;
}
}
}
int q;
cin >> q;
while (q--) {
int d;
char a, b;
cin >> d >> a >> b;
int x = a - 'a';
int y = b - 'a';
cout << dp[d][x][y] << '\n';
}
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
5 ms |
852 KB |
Output is correct |
2 |
Correct |
4 ms |
728 KB |
Output is correct |
3 |
Correct |
4 ms |
724 KB |
Output is correct |
4 |
Correct |
6 ms |
836 KB |
Output is correct |
5 |
Correct |
35 ms |
3532 KB |
Output is correct |
6 |
Correct |
37 ms |
3660 KB |
Output is correct |
7 |
Correct |
32 ms |
3316 KB |
Output is correct |
8 |
Correct |
30 ms |
3040 KB |
Output is correct |
9 |
Execution timed out |
2100 ms |
17104 KB |
Time limit exceeded |
10 |
Execution timed out |
2094 ms |
17100 KB |
Time limit exceeded |