spoj5973

SP5973 SELTEAM - Selecting Teams

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
inline ll read()
{
    ll s=0; bool f=0; char ch=‘ ‘;
    while(!isdigit(ch)) {f|=(ch==‘-‘); ch=getchar();}
    while(isdigit(ch)) {s=(s<<3)+(s<<1)+(ch^48); ch=getchar();}
    return (f)?(-s):(s);
}
#define R(x) x=read()
inline void write(ll x)
{
    if(x<0) {putchar(‘-‘); x=-x;}
    if(x<10) {putchar(x+‘0‘); return;}
    write(x/10); putchar((x%10)+‘0‘);
}
#define W(x) write(x),putchar(‘ ‘)
#define Wl(x) write(x),putchar(‘\n‘)
const int N=100005;
const ll Mod=8388608;
ll T,n,k;
ll C[N][25];
inline void Ad(ll &x,ll y)
{
    x+=y; x-=(x>=Mod)?Mod:0;
}
int main()
{
    ll i,j,ans;
    R(T);
    C[0][0]=1;
    for(i=1;i<=100000;i++)
    {
        C[i][0]=1; for(j=1;j<=min(23ll,i);j++) C[i][j]=(C[i-1][j]+C[i-1][j-1])%Mod;
    }
    while(T--)
    {
        R(n); R(k); ans=0;
        for(i=1;i<=min(k,23ll);i++) Ad(ans,C[n][i]*i%Mod*(1ll<<(i-1))%Mod);
        Wl(ans);
    }
    return 0;
}
/*
input
3
2 2
7 1
5 3
output
6
7
165
*/

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