Submission #1208031

#	Time	Username	Problem	Language	Result	Execution time	Memory
1208031		mychecksedad	Sparklers (JOI17_sparklers)	C++20	0 / 100	0 ms	320 KiB

sparklers

/* Author : Mychecksdead  */
#include<bits/stdc++.h>
using namespace std;
#define ll long long int
#define MOD (1000000000+7)
#define MOD1 (998244353)
#define pb push_back
#define all(x) x.begin(), x.end()
#define en cout << '\n'
#define ff first
#define ss second
#define pii pair<int,int>
#define vi vector<int>
const int N = 1e6+100, M = 1e5+10, K = 52, MX = 30;


int n, k;
ll t, a[N];
void solve(){
  cin >> n >> k >> t;
  for(int i = 1; i <= n; ++i){
    cin >> a[i];
  }

  ll l = 0, r = 1e9, ans = 1e9;
  while(l <= r){
    ll mid = l+r>>1;
    bool ok = false;
    for(int mask = 0; mask < (1<<(n-1)); ++mask){
      if(__builtin_popcount(mask) != k - 1) continue;
      // 1's go left, 0's go right
      ll mn = a[k], mx = a[k];
      bool oo = true;
      int L = k, R = k;
      if(mid == 7)
      for(int i = 0; i < n-1; ++i){
        if((1<<i)&mask){
          // if(mid==7){
          //   cerr << i << ' ' << a[L] + (a[R] - a[L + 1]) << '\n';
          // }
          --L; // we will get a[L-1]
          if(mn > a[L] + (a[R] - mn) + t * mid * 2){
            oo = false;
            break;
          }
          mx = a[L] + (a[R] - mn) + t * mid;
          mn = mn - t * mid;
        }else{
          ++R; // we will get a[L-1]
          if(mx < a[R] - (mx - a[L]) - t * mid * 2){
            oo = false;
            break;
          }
          mn = a[R] - (mx - a[L]) - t * mid;
          mx = mx + t * mid;
        }
      }
      if(oo){
        ok = 1;
        break;
      }
    }
    if(ok){
      ans = mid;
      r = mid-1;
    }else l = mid+1;
  }

  cout << ans;
}


int main(){
  cin.tie(0); ios::sync_with_stdio(0);
  int tt = 1, aa;
  // freopen("in.txt", "r", stdin);
  // freopen("out.txt", "w", stdout);
  while(tt--){
    solve();
    en;
  }
  cerr<<"time taken : "<<(float)clock()/CLOCKS_PER_SEC<<" seconds\n";
  return 0;
} 

• Subtask 1: 0 / 30
• Subtask 2: 0 / 20
• Subtask 3: 0 / 50