'commit'

TangDou/AcWing/SegmentTree/248_1.cpp

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+#include <iostream>
+#include <algorithm>
+#include <cmath>
+#include <cstring>
+#include <vector>
+
+using namespace std;
+typedef long long LL;
+const int N = 10010;
+
+//在对 x 坐标进行升序排序时，将 k 值按降序排序，这样才能处理两个矩形贴合的情况
+struct Seg {
+    LL x, y1, y2, c;
+    bool operator<(const Seg &t) const {
+        if (x == t.x) return c > t.c; // 1在前，-1在后，先处理入边再处理出边
+        return x < t.x;
+    }
+} seg[N << 1];
+
+struct Node {
+    int l, r;
+    int maxc, add;
+} tr[N << 3];
+
+int n, w, h;
+vector<LL> ys;
+
+void pushup(int u) {
+    tr[u].maxc = max(tr[u << 1].maxc, tr[u << 1 | 1].maxc);
+}
+
+void build(int u, int l, int r) {
+    tr[u] = {l, r, 0, 0};
+    if (l == r) return;
+    int mid = (l + r) >> 1;
+    build(u << 1, l, mid);
+    build(u << 1 | 1, mid + 1, r);
+}
+
+void pushdown(int u) {
+    if (tr[u].add) {
+        tr[u << 1].maxc += tr[u].add;
+        tr[u << 1].add += tr[u].add;
+        tr[u << 1 | 1].maxc += tr[u].add;
+        tr[u << 1 | 1].add += tr[u].add;
+        tr[u].add = 0;
+    }
+}
+
+void modify(int u, int l, int r, int c) {
+    if (l <= tr[u].l && tr[u].r <= r) {
+        tr[u].maxc += c;
+        tr[u].add += c;
+        return;
+    }
+
+    pushdown(u);
+    int mid = tr[u].l + tr[u].r >> 1;
+    if (l <= mid) modify(u << 1, l, r, c);
+    if (r > mid) modify(u << 1 | 1, l, r, c);
+
+    pushup(u);
+}
+
+int find(LL x) {
+    return lower_bound(ys.begin(), ys.end(), x) - ys.begin();
+}
+
+int main() {
+    //加快读入
+    ios::sync_with_stdio(false), cin.tie(0);
+
+    while (cin >> n >> w >> h) {
+        ys.clear();
+        for (int i = 1; i <= n; i++) {
+            LL x, y;
+            int c;
+            cin >> x >> y >> c;
+            //区别在这里！
+            /*
+            需配合：
+            if (x == t.x) return c > t.c; // 1在前，-1在后，先处理入边再处理出边
+            */
+            seg[2 * i - 1] = {x, y, y + h - 1, c};
+            //此处,x+w-1,注意：多减了一个1~
+            seg[2 * i] = {x + w - 1, y, y + h - 1, -c};
+            ys.push_back(y), ys.push_back(y + h - 1);
+        }
+
+        sort(ys.begin(), ys.end());
+        ys.erase(unique(ys.begin(), ys.end()), ys.end());
+
+        sort(seg + 1, seg + 1 + 2 * n);
+
+        build(1, 0, ys.size() - 1);
+
+        int res = 0;
+        for (int i = 1; i <= 2 * n; i++) {
+            res = max(res, tr[1].maxc);
+            modify(1, find(seg[i].y1), find(seg[i].y2), seg[i].c);
+        }
+        printf("%d\n", res);
+    }
+    return 0;
+}