LightOJ 1231 Coin Change(I)

// aarifshuvo   ``CSEJU 

#include <bits/stdc++.h>
#define ll long long
#define SZ(x) ((int)(x).size())
#define ALL(x) (x).begin(),(x).end()
#define REP(i,n) for(int i=0;i<n;i++)
#define REV(i,n) for(int i=n-1;i>=0;i--)
#define FOR(i,a,b) for(int i=a;i<=b;i++)
#define pri(a) cout<<a<<endl
using namespace std;

ll coins[52], times[52];
ll n,k;
ll dp[52][1008];

ll call(ll i, ll feas)
{
    if(feas==0) return 1;
    if(i==n) return 0;

    if(dp[i][feas]!=-1) return dp[i][feas];

    dp[i][feas] = 0;

    for(int j=0; j<=times[i] && feas-j*coins[i]>=0 ;j++)
    {
        dp[i][feas] += call(i+1,feas-j*coins[i])%100000007;
    }
    return dp[i][feas]%100000007;
}

int main()
{
    ll T,cs=0;
    scanf("%lld", &T);
    while(T--)
    {
        memset(dp, -1, sizeof dp);

        scanf("%lld%lld", &n, &k);
        REP(i,n) scanf("%lld", &coins[i]);
        REP(i,n) scanf("%lld", &times[i]);

        printf("Case %lld: %lld\n", ++cs, call(0,k));
    }
    return 0;
}