#include <iostream>
#include <vector>
#include <set>
#include <cstring>
#define DIM 2010
#define MOD 1000000007
using namespace std;
//ifstream cin ("date.in");
//ofstream cout ("date.out");
int v[DIM],c[DIM][DIM],f[DIM],dp[DIM][30][30],a[DIM][30];
vector <int> pozx,pozy;
set <int> L;
char s[DIM],l1,l2;
int n,i,j,x,y,q,lg;
int main (){
cin>>s+1;
n = strlen(s+1);
for (i=1;i<=n;i++)
v[i] = s[i] - 'a' + 1;
c[0][0] = c[1][0] = c[1][1] = 1;
for (i=2;i<=n;i++){
c[i][0] = 1;
for (j=1;j<=i;j++)
c[i][j] = (c[i-1][j] + c[i-1][j-1])%MOD;
}
/// a[i][x] - in cate moduri pot selecta s[i],j (am nevoie sa stiu pozitia primului)
for (i=1;i<=n;i++)
for (j=i+1;j<=n;j++)
a[i][v[j]]++;
/// dp[i][x][y] - cate siruri de lungime i care se termina cu xy pot obtine
for (lg=2;lg<=n;lg++){
for (i=lg;i<=n;i++){
x = v[i];
for (y=1;y<=26;y++)
dp[lg][x][y] = (dp[lg][x][y]+a[i][y]*c[i-1][lg-2]%MOD)%MOD;
}}
/*for (x=1;x<=26;x++)
for (y=1;y<=26;y++){
if (x == 14 && y == 14)
x = 14;
pozy.clear(), pozx.clear(), L.clear();
memset (f,0,sizeof f);
for (i=1;i<=n;i++)
if (v[i] == y)
pozy.push_back(i);
int idx = 0;
for (i=1;i<=n;i++){
if (pozy[idx] == i){
for (j=0;j<pozx.size();j++){
L.insert(pozx[j]-1); /// pana unde pot selecta caractere
f[pozx[j]-1]++;
}
if (idx == pozy.size()-1)
break;
idx++;
}
if (v[i] == x)
pozx.push_back(i);
}
/// dp[i][x][y] - cate siruri de lungime i care se termina cu xy pot obtine
for (i=2;i<=n;i++)
for (set<int>:: iterator it=L.begin();it!=L.end();it++){
int lg = *it;
dp[i][x][y] = (dp[i][x][y] + c[lg][i-2]*f[lg]%MOD)%MOD;
}}*/
cin>>q;
for (;q--;){
cin>>lg>>l1>>l2;
x = l1-'a'+1, y = l2-'a'+1;
cout<<dp[lg][x][y]<<"\n";
}
return 0;
}
Compilation message
mate.cpp: In function 'int main()':
mate.cpp:18:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
cin>>s+1;
~^~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
88 ms |
760 KB |
Output isn't correct |
| 2 |
Incorrect |
58 ms |
760 KB |
Output isn't correct |
| 3 |
Incorrect |
68 ms |
760 KB |
Output isn't correct |
| 4 |
Incorrect |
116 ms |
904 KB |
Output isn't correct |
| 5 |
Incorrect |
413 ms |
2808 KB |
Output isn't correct |
| 6 |
Incorrect |
470 ms |
3064 KB |
Output isn't correct |
| 7 |
Incorrect |
360 ms |
2808 KB |
Output isn't correct |
| 8 |
Incorrect |
323 ms |
2680 KB |
Output isn't correct |
| 9 |
Execution timed out |
2048 ms |
27760 KB |
Time limit exceeded |
| 10 |
Execution timed out |
2050 ms |
27976 KB |
Time limit exceeded |
