Submission #2067167

---

Source Code Expand

#include <bits/stdc++.h>

using namespace std;

#define int long long
#define all(v) (v).begin(), (v).end()
#define resz(v, ...) (v).clear(), (v).resize(__VA_ARGS__)
#define reps(i, m, n) for(int i = (int)(m); i < (int)(n); i++)
#define rep(i, n) reps(i, 0, n)

template<class T1, class T2> void chmin(T1 &a, T2 b){if(a>b)a=b;}
template<class T1, class T2> void chmax(T1 &a, T2 b){if(a<b)a=b;}

using Pi = pair<int, int>;
using Tapris = tuple<int, int, int>;
using vint = vector<int>;

const int inf = 1LL << 55;
const int mod = 1e9 + 7;

signed main() {
  cin.tie(0);
  ios_base::sync_with_stdio(0);
  cout << fixed << setprecision(12);

  int N, L;
  cin >> N >> L; L *= 10;
  vint x(N);
  rep(i, N) cin >> x[i], x[i] *= 10;

  int l = 0, r = 0; // l:次に飛ぶハードル, r:lと一緒に飛べるハードル
  int pos = 1; // ??.1の位置でジャンプ/着地する
  while(r < N) {
    while(r+1 < N && x[r+1]-x[l] < L) ++r;
    pos = max(pos+L, x[r]+1);
    if(r+1 >= N) break;
    if(x[r+1]-pos < L) {
      cout << "NO" << endl;
      return 0;
    }
    pos += L;
    l = r+1;
  }
  cout << "YES" << endl;

  return 0;
}

Submission Info

Judge Result