Submission #2553472

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Source Code Expand

#include <algorithm>
#include <cstring>
#include <deque>
#include <functional>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <vector>
using namespace std;
using ll = long long;

int main() {
  int N;
  ll L;
  while (cin >> N >> L) {
    vector<ll> x(N);
    for (int i = 0; i < N; i++) cin >> x[i];
    x.push_back(1ll << 50);
    bool ok = true;
    ll p = 0;
    int j = 0;
    for (int i = 0; i < N; i++) {
      if (x[i + 1] - x[i] >= L) {
        ll jp = max(p, x[i] - L);
        if (x[j] <= jp) {
          ok = false;
          break;
        }
        p = jp + 2 * L;
        j = i + 1;
      }
    }
    cout << (ok ? "YES" : "NO") << endl;
  }
  return 0;
}

Submission Info

Judge Result