百度之星资格赛 2016 Problem 1001

1 const int mod = 9973;
2 LL Inverse[mod + 7];
3 Inverse[0] = 0, Inverse[1] = 1;
4 for(int i = 2; i < mod; i++)
5     Inverse[i] = ( - ( mod / i ) * Inverse[ mod % i ] ) % mod + mod;

 1 const int maxN = 1000000 + 7;
 2 const int p = 9973;
 3 LL ni[p];
 4 char str[maxN];
 5 LL a[maxN];
 6 
 7 int main(){
 8     //freopen("input.txt", "r", stdin);
 9     ni[1] = 1;
10     ni[0] = 0;
11     for(int i = 2; i < p; i++)
12         ni[i] = (-(p/i) * ni[p%i]) % p + p;
13     int n;
14     while(~scanf("%d", &n))
15     {
16         scanf("%s", str);
17         int len = strlen(str);
18         a[0] = 1;
19         for(int i = 1; i <= len; i++)
20             a[i] = a[i - 1] * (str[i - 1] - 28) % p;
21         while(n--){
22             int s, m;
23             scanf("%d%d", &s, &m);
24             printf("%I64d\n", a[m] * ni[a[s - 1]] % p);
25         }
26     } 
27     return 0;
28 }