'commit'

TangDou/AcWing/SegmentTree/HDU1828_Heng.cpp

@@ -0,0 +1,101 @@
+#include <bits/stdc++.h>
+using namespace std;
+typedef long long LL;
+const int N = 10010;
+
+struct ScanLine {
+    int x1, x2, y, mark;
+    const bool operator<(const ScanLine &t) const {
+        if (y == t.y) return mark > t.mark;
+        return y < t.y;
+    }
+
+} line[N];
+
+struct Node {
+    int l, r;
+    int cnt, len;
+    int c;
+    bool lc, rc;
+
+} tr[N << 2];
+
+int b[N];
+
+void pushup(int u) {
+    int l = tr[u].l, r = tr[u].r;
+    if (tr[u].cnt) {
+        tr[u].len = b[r + 1] - b[l];
+        tr[u].c = 2;
+        tr[u].lc = tr[u].rc = 1;
+    } else {
+        tr[u].len = tr[u << 1].len + tr[u << 1 | 1].len;
+        tr[u].c = tr[u << 1].c + tr[u << 1 | 1].c;
+        if (tr[u << 1 | 1].lc && tr[u << 1].rc) tr[u].c -= 2;
+        tr[u].lc = tr[u << 1].lc;
+        tr[u].rc = tr[u << 1 | 1].rc;
+    }
+}
+
+void modify(int u, int l, int r, int v) {
+    if (l <= tr[u].l && r >= tr[u].r) {
+        tr[u].cnt += v;
+        pushup(u);
+        return;
+    }
+    int mid = (tr[u].l + tr[u].r) >> 1;
+    if (l <= mid) modify(u << 1, l, r, v);
+    if (r > mid) modify(u << 1 | 1, l, r, v);
+    pushup(u);
+}
+
+void build(int u, int l, int r) {
+    tr[u].l = l, tr[u].r = r;
+    if (l == r) return;
+    int mid = (l + r) >> 1;
+    build(u << 1, l, mid);
+    build(u << 1 | 1, mid + 1, r);
+}
+
+int main() {
+#ifndef ONLINE_JUDGE
+    freopen("HDU1828.in", "r", stdin);
+#endif
+
+    ios::sync_with_stdio(false), cin.tie(0);
+    int n;
+    while (cin >> n) {
+        memset(tr, 0, sizeof tr);
+        int x1, y1, x2, y2;
+        for (int i = 1; i <= n; i++) {
+            cin >> x1 >> y1 >> x2 >> y2;
+            line[i * 2 - 1] = {x1, x2, y1, 1};
+            line[i * 2] = {x1, x2, y2, -1};
+            b[i * 2 - 1] = x1, b[i * 2] = x2;
+        }
+
+        n <<= 1;
+
+        sort(line + 1, line + n + 1);
+        sort(b + 1, b + n + 1);
+        int tot = unique(b + 1, b + 1 + n) - b - 1;
+
+        build(1, 1, tot - 1);
+
+        LL res = 0;
+        int last = 0;
+
+        for (int i = 1; i < n; i++) {
+            int L = lower_bound(b + 1, b + tot + 1, line[i].x1) - b;
+            int R = lower_bound(b + 1, b + tot + 1, line[i].x2) - b;
+            modify(1, L, R - 1, line[i].mark);
+
+            res += (LL)tr[1].c * (line[i + 1].y - line[i].y);
+            res += (LL)abs(tr[1].len - last);
+            last = tr[1].len;
+        }
+        res += line[n].x2 - line[n].x1;
+        printf("%lld\n", res);
+    }
+    return 0;
+}