#include <iostream>
#include <cstring>
#define MOD 1000000007
using namespace std;
long long Q,d,i,j,comb[2005][2005],D[2005][30][30];
long long r[2005][30],poz[30][2005],sol[2005][30][30];
char s[2005],x,y;
int main()
{
cin >> (s+1);
int n = strlen((s+1));
comb[0][0] = 1;
for (i=1; i<=n; i++)
{
comb[i][0] = comb[i][i] = 1;
for (j=1; j<i; j++)
comb[i][j] = (comb[i-1][j-1]+comb[i-1][j])%MOD;
}
for (i=1; i<=n; i++)
poz[s[i]-'a'][++poz[s[i]-'a'][0]] = i;
for (i=n; i>=1; i--)
for (j=0; j<26; j++)
if (s[i] == 'a'+j)
r[i][j] = 1+r[i+1][j];
else
r[i][j] = r[i+1][j];
for (i=n; i>=1; i--)
for (j=0; j<26; j++)
for (int k=0; k<26; k++)
if (s[i] == 'a'+j)
D[i][j][k] = r[i+1][k];
else
D[i][j][k] = D[i+1][j][k];
for (int l=2; l<=n; l++)
for (j=0; j<26; j++)
for (int t=1; t<=poz[j][0]; t++)
{
i = poz[j][t];
if (i >= l-1)
for (int k=0; k<26; k++)
sol[l][j][k] += (D[i][j][k]*comb[i-1][l-2])%MOD;
}
cin >> Q;
for (;Q--;)
{
cin >> d >> x >> y;
cout << sol[d][x-'a'][y-'a'] << "\n";
}
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
88 ms |
1400 KB |
Output is correct |
| 2 |
Incorrect |
60 ms |
1272 KB |
Output isn't correct |
| 3 |
Incorrect |
69 ms |
1272 KB |
Output isn't correct |
| 4 |
Incorrect |
116 ms |
1400 KB |
Output isn't correct |
| 5 |
Incorrect |
418 ms |
5280 KB |
Output isn't correct |
| 6 |
Incorrect |
517 ms |
5368 KB |
Output isn't correct |
| 7 |
Incorrect |
359 ms |
5240 KB |
Output isn't correct |
| 8 |
Incorrect |
327 ms |
5112 KB |
Output isn't correct |
| 9 |
Execution timed out |
2056 ms |
57608 KB |
Time limit exceeded |
| 10 |
Execution timed out |
2069 ms |
57596 KB |
Time limit exceeded |
