P3353 在你窗外闪耀的星星

R52389184

Luogu/problem/P3353/P3353.cpp

@@ -0,0 +1,68 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+struct node {
+    int l, r, s;
+
+    node() {
+        l = r = s = 0;
+    }
+    node(int _l, int _r) {
+        l = _l;
+        r = _r;
+        s = 0;
+    }
+} tr[1000005 << 2];
+int n, w, x, b, ans;
+
+void pushup(int u) {
+    tr[u].s = tr[u << 1].s + tr[u << 1 | 1].s;
+}
+
+void build(int u, int l, int r) {
+    tr[u] = node(l, r);
+    if (l == r) return;
+    int mid = l + r >> 1;
+    build(u << 1, l, mid);
+    build(u << 1 | 1, mid + 1, r);
+}
+
+void modify(int u, int p, int d) {
+    if (tr[u].l == p == tr[u].r) {
+        tr[u].s += d;
+        return;
+    }
+    int mid = tr[u].l + tr[u].r >> 1;
+    if (p <= mid) {
+        modify(u << 1, p, d);
+    } else {
+        modify(u << 1 | 1, p, d);
+    }
+    pushup(u);
+}
+
+int query(int u, int l, int r) {
+    if (l <= tr[u].l && tr[u].r <= r) {
+        return tr[u].s;
+    }
+    int mid = tr[u].l + tr[u].r >> 1;
+    int s = 0;
+    if (l <= mid) s += query(u << 1, l, r);
+    if (r > mid) s += query(u << 1 | 1, l, r);
+    return s;
+}
+
+int main() {
+    cin >> n >> w;
+    build(1, 1, 100000);
+    for (int i = 0; i < n; i++) {
+        cin >> x >> b;
+        modify(1, x, b);
+    }
+    for (int i = 1; i + w <= 100000; i++) {
+        ans = max(ans, query(1, i, i + w - 1));
+    }
+    cout << ans << endl;
+    return 0;
+}