计算系数

题面

杨辉三角

#include <cstdio>
#include <iostream>
using namespace std;
#include <cmath>
#include <string>
#include <cstring>
#include <queue>
#include <stack>
#include <map>
#include <list>
#include <deque>
#include <climits>
#include <algorithm>
#include <ctime>
#include <cstdlib>
#define ll long long
#define MOD 10007
#define N 2100
#define R register ll

ll a,b,k,n,m;
ll g[N][N];

inline void INIT()
{
    g[1][1]=1;
    for (R i=2;i<=k+1;i++)
    {
        for (R j=1;j<=i;j++)
        {
            g[i][j]=(g[i-1][j-1]%MOD+g[i-1][j]%MOD)%MOD;
        }
    }
}

inline ll mypow(ll aa,ll bb)
{
    ll lh=aa;
    for (R i=2;i<=bb;i++)
    {
        lh*=aa;
        lh%=MOD;
    }
    return lh;
}

int main()
{
    //freopen("factor.in","r",stdin);
    //freopen("factor.out","w",stdout);
    scanf("%lld%lld%lld%lld%lld",&a,&b,&k,&n,&m);
    INIT();
    printf("%lld",((((g[k+1][k-n+1]%MOD)*mypow(a,n))%MOD)*mypow(b,m))%MOD);
    fclose(stdin);
    fclose(stdout);
    return 0;
}