BZOJ2982: combination

  1 #include<cstdio>
  2 
  3 #include<cstdlib>
  4 
  5 #include<cmath>
  6 
  7 #include<cstring>
  8 
  9 #include<algorithm>
 10 
 11 #include<iostream>
 12 
 13 #include<vector>
 14 
 15 #include<map>
 16 
 17 #include<set>
 18 
 19 #include<queue>
 20 
 21 #include<string>
 22 
 23 #define inf 1000000000
 24 
 25 #define maxn 500+100
 26 
 27 #define maxm 500+100
 28 
 29 #define eps 1e-10
 30 
 31 #define ll long long
 32 
 33 #define pa pair<int,int>
 34 
 35 #define for0(i,n) for(int i=0;i<=(n);i++)
 36 
 37 #define for1(i,n) for(int i=1;i<=(n);i++)
 38 
 39 #define for2(i,x,y) for(int i=(x);i<=(y);i++)
 40 
 41 #define for3(i,x,y) for(int i=(x);i>=(y);i--)
 42 
 43 #define mod 10007
 44 
 45 using namespace std;
 46 
 47 inline int read()
 48 
 49 {
 50 
 51     int x=0,f=1;char ch=getchar();
 52 
 53     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
 54 
 55     while(ch>=‘0‘&&ch<=‘9‘){x=10*x+ch-‘0‘;ch=getchar();}
 56 
 57     return x*f;
 58 
 59 }
 60 int n,m,cs;
 61 int power(int x,int y)
 62 {
 63     int t=1;
 64     for(;y;y>>=1,x*=x,x%=mod)
 65         if(y&1)t*=x,t%=mod;
 66     return t;
 67 }
 68 int getc(int n,int m)
 69 {
 70     if(n<m)return 0;
 71     m=max(m,n-m);
 72     int t1=1,t2=1;
 73     for2(i,m+1,n)t1*=i,t1%=mod;
 74     for2(i,2,n-m)t2*=i,t2%=mod;
 75     return (t1*power(t2,mod-2))%mod;
 76 }
 77     
 78 inline int lucas(int n,int m)
 79 {
 80     return m?(getc(n%mod,m%mod)*lucas(n/mod,m/mod))%mod:1;
 81 }
 82 
 83 int main()
 84 
 85 {
 86 
 87     freopen("input.txt","r",stdin);
 88 
 89     freopen("output.txt","w",stdout);
 90 
 91     cs=read();
 92     while(cs--)
 93     {
 94         n=read();m=read();
 95         printf("%d\n",lucas(n,m));
 96     }
 97 
 98     return 0;
 99 
100 }