Submission #534315

#	Time	Username	Problem	Language	Result	Execution time	Memory
534315		cig32	Ice Hockey World Championship (CEOI15_bobek)	C++17	100 / 100	500 ms	10236 KiB

bobek

#include "bits/stdc++.h"
using namespace std;
const int MAXN = 2e5 + 10;
const int MOD = 1e9 + 7;
#define int long long
mt19937_64 rng((int)std::chrono::steady_clock::now().time_since_epoch().count());
int rnd(int x, int y) {
  int u = uniform_int_distribution<int>(x, y)(rng); return u;
}
int bm(int b, int p) { 
  if(p==0) return 1;
  int r = bm(b, p/2);
  if(p&1) return (((r*r) % MOD) * b) % MOD;
  return (r*r) % MOD;
}
int inv(int b) {
  return bm(b, MOD-2);
}
int f[MAXN];
int nCr(int n, int r) { 
  int ans = f[n]; ans *= inv(f[r]); ans %= MOD;
  ans *= inv(f[n-r]); ans %= MOD; return ans;
}

void precomp() { 
  f[0] = 1;
  for(int i=1; i<MAXN; i++) f[i] = (f[i-1] * i) % MOD;
}

void solve(int tc) {
  int n, m;
  cin >> n >> m;
  vector<int> l, r;
  for(int i=0; i<n/2; i++) {
    int x;cin >> x;
    l.push_back(x);
  }
  for(int i=0; i<n-n/2; i++) {
    int x;cin >> x;
    r.push_back(x);
  }
  vector<int> v;
  int L = l.size();
  for(int i=0; i<(1<<L); i++) {
    int e = 0;
    for(int j=0; j<L; j++) {
      if(i & (1<<j)) {
        e += l[j];
      }
    }
    v.push_back(e);
  }
  sort(v.begin(), v.end());
  int R = r.size();
  int ans = 0;
  for(int i=0; i<(1<<R); i++) {
    int e = 0;
    for(int j=0; j<R; j++) {
      if(i & (1<<j)) {
        e += r[j];
      }
    }
    int lb = 0, rb = v.size() - 1;
    while(lb < rb) {
      int mid = (lb + rb + 1) >> 1;
      if(v[mid] + e <= m) lb = mid;
      else rb = mid - 1;
    }
    if(v[lb] + e <= m) ans += lb + 1;
  }
  cout << ans << "\n";
}
int32_t main(){
  precomp();
  ios::sync_with_stdio(0); cin.tie(0);
  int t = 1; //cin >> t;
  for(int i=1; i<=t; i++) solve(i);
} 

• Subtask 1: 10 / 10
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 10 / 10
• Subtask 5: 10 / 10
• Subtask 6: 10 / 10
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 10 / 10
• Subtask 10: 10 / 10