P3594 [POI2015] WIL

https://www.luogu.com.cn/record/77767878

Luogu/P3594/P3594.cpp

@@ -0,0 +1,47 @@
+#include <iostream>
+#include <deque>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 2e6 + 5;
+
+int n, d, a[N], ans;
+long long p, sum, s[N], t[N];
+std::deque<int> q;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n >> p >> d;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> a[i];
+
+        s[i] = s[i - 1] + a[i];
+    }
+
+    for (int i = 1; i <= n; i++) {
+        t[i] = s[i] - s[i - d];
+    }
+
+    ans = d;
+    sum = s[d + 1];
+    q.push_back(d);
+
+    for (int i = d + 1, l = 1, r = 0; i <= n; sum += a[++i]) {
+        while (!q.empty() && t[q.back()] <= t[i]) q.pop_back();
+        q.push_back(i);
+        while (sum - t[q.front()] > p) {
+            if (q.front() < l + d) q.pop_front();
+            sum -= a[l++];
+        }
+        ans = std::max(ans, i - l + 1);
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}