2023 rcpc

2023/rcpc/d1/editorial/F. Difference In Skill - monotone stack.cpp

@@ -0,0 +1,45 @@
+/// Banu Denis - monotone stack solution
+#include <bits/stdc++.h>
+
+using namespace std;
+
+#define ll long long
+#define ld long double
+#define ull unsigned long long
+#define pii pair<int,int>
+#define MOD 1000000007
+#define zeros(x) x&(x-1)^x
+#define fi first
+#define se second
+#define NMAX 200005
+const long double PI = acos(-1);
+
+int n,k,ans[NMAX];
+deque<pii> bst;
+vector<pair<int, int> > v;
+
+int main(){
+  ios::sync_with_stdio(false);
+  cin >> n >> k;
+  for (int i=1;i<=n;i++) {
+    int x;
+    cin >> x;
+    v.push_back({x, i});
+  }
+  sort(v.begin(), v.end());
+  v.push_back({int(2e9) + 3, 0});
+
+  int st = 0, dr = -1;
+  while (st < n) {
+    while (v[st].first + k >= v[dr+1].first) dr++;
+    while (!bst.empty() && bst.back().first <= dr-st+1) bst.pop_back();
+    bst.push_back({dr-st+1, dr});
+    while (!bst.empty() && bst.front().second < st) bst.pop_front();
+    ans[v[st].second] = bst.front().first;
+    st++;
+  }
+
+  for (int i=1;i<=n;i++) cout << ans[i] << ' ';
+  cout << '\n';
+  return 0;
+}