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Record Detail

Wrong Answer


  
# Status Time Cost Memory Cost
#1 Accepted 3ms 1.281 MiB
#2 Accepted 3ms 1.074 MiB
#3 Wrong Answer 5ms 1.277 MiB
#4 Accepted 4ms 1.277 MiB
#5 Accepted 5ms 1.293 MiB
#6 Wrong Answer 3ms 1.293 MiB

Code

#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define dbg(a,b,c,d) cerr<<a<<"  "<<b<<"  "<<c<<"  "<<d<<endl;
#define kill(a) {cout<<a<<endl;continue;}
#define KILL(a) {cout<<a<<endl;return 0;}
#define debug cerr<<"Error Found"<<endl;
#define mem(a,b) memset(a,b,sizeof(a))
#define lcm(a, b) (a/__gcd(a,b))*b
#define w(t) cin>>t;while(t--)
#define pi  2 * acos(0.0)
#define endl "\n"
int t, cs = 0;
const int mxn = 2e5 + 3, mod = 1e9 + 7;
int fact[mxn];
int power(int base, int po)
{
    int res = 1;
    while(po)
    {
        if(po & 1)res = 1LL * base * res % mod;
        base = 1LL * base * base % mod, po /= 2;
    }
    return res;
}
void pre()
{
    fact[0] = 1;
    for(int i = 1; i < mxn; i++)fact[i] = 1LL * fact[i - 1] * i % mod;
}
int ncr(int n, int r)
{
    if(r > n)return 0;
    int ans = fact[n];
    ans = 1LL * ans * power(fact[n - r], mod - 2) % mod;
    ans = 1LL * ans * power(fact[r], mod - 2) % mod;
    return ans;
}
int32_t main()
{
    //fast
    pre();
    w(t)
    {
        int n, k;
        cin >> n >> k;
        int ar[n + 1];
        int sum = 0;
        for(int i = 1; i <= n; i++)cin >> ar[i], sum += ar[i];
        if(k > sum)kill(0);
        int ans = power(2, n - sum);
        ans--;
        if(!k)
        {
            if(ans < 0)ans += mod;
            kill(ans);
        }
        int rans = 0;
        for(int i = k; i < sum; i++)rans += ncr(sum, i), rans %= mod;

        int ex = (ans + rans) % mod;
        ans = 1LL * ans * rans % mod, ans %= mod, ans += ex, ans %= mod;
        cout << ans << endl;

    }
}

Information

Submit By
Type
Submission
Problem
P1093 Number of Ways (Easy version)
Language
C++17 (G++ 13.2.0)
Submit At
2024-12-03 16:43:12
Judged At
2024-12-03 16:43:12
Judged By
Score
13
Total Time
5ms
Peak Memory
1.293 MiB