HDU6027-Easy Summation-简单数学

//传送门：http://acm.hdu.edu.cn/showproblem.php?pid=6027#include <iostream>#include <cstdio>#include <algorithm>#include <cstring>#include <string>#include <cmath>#include <vector>#include <queue>#include <stack>#include <set>#include <map>using namespace std;#define FOR(i,k,n) for(int i=k;i<n;i++)#define FORR(i,k,n) for(int i=k;i<=n;i++)#define scan(a) scanf("%d",&a)#define scann(a,b) scanf("%d%d",&a,&b)#define scannn(a,b,c) scanf("%d%d%d",&a,&b,&c)#define mst(a,n)  memset(a,n,sizeof(a))#define ll long long#define N 1005#define mod 1000000007#define INF 0x3f3f3f3fconst double eps=1e-8;const double pi=acos(-1.0);int main(){    //freopen("in.txt","r",stdin);    //freopen("out.txt","w",stdout);    int t;    cin>>t;    while(t--)    {        ll n,k;        cin>>n>>k;        ll ans=0;        for(ll i=1;i<=n;i++)        {            ll tmp=1;            for(ll j=0;j<k;j++)            {                tmp=tmp*i%mod;            }            ans=(ans+tmp)%mod;        }        cout<<ans<<endl;    }    return 0;}