#112. 三维偏序

https://loj.ac/s/1479954

LibreOJ/112/112.go

@@ -0,0 +1,137 @@
+package main
+
+import (
+    "fmt"
+    "sort"
+)
+
+const N int = 1e5 + 5
+const K int = 2e5 + 5
+
+type node struct {
+    a, b, c, cnt, res int
+}
+
+var (
+    q      []node
+    w      [N]node
+    c, ans [K]int
+)
+
+func lowbit(x int) int {
+    return x & -x
+}
+
+func add(x, y int) {
+    for ; x <= 2e5; x += lowbit(x) {
+        c[x] += y
+    }
+}
+
+func sum(x int) int {
+    var res int = 0
+
+    for ; x > 0; x -= lowbit(x) {
+        res += c[x]
+    }
+
+    return res
+}
+
+func mergeSort(l, r int) {
+    if l >= r {
+        return
+    }
+
+    var mid = (l + r) / 2
+
+    mergeSort(l, mid)
+    mergeSort(mid+1, r)
+
+    var i, j, k = l, mid + 1, 0
+
+    for i <= mid && j <= r {
+        if q[i].b <= q[j].b {
+            add(q[i].c, q[i].cnt)
+            k++
+            w[k] = q[i]
+            i++
+        } else {
+            q[j].res += sum(q[j].c)
+            k++
+            w[k] = q[j]
+            j++
+        }
+    }
+
+    for i <= mid {
+        add(q[i].c, q[i].cnt)
+        k++
+        w[k] = q[i]
+        i++
+    }
+
+    for j <= r {
+        q[j].res += sum(q[j].c)
+        k++
+        w[k] = q[j]
+        j++
+    }
+
+    for i = l; i <= mid; i++ {
+        add(q[i].c, -q[i].cnt)
+    }
+
+    for i, j := l, 1; j <= k; j++ {
+        q[i] = w[j]
+        i++
+    }
+}
+
+func main() {
+    var n, k int
+
+    fmt.Scan(&n, &k)
+
+    q = append(q, node{})
+
+    for i := 1; i <= n; i++ {
+        var a, b, c int
+
+        fmt.Scan(&a, &b, &c)
+
+        q = append(q, node{a, b, c, 1, 0})
+    }
+
+    sort.Slice(q, func(x, y int) bool {
+        if q[x].a != q[y].a {
+            return q[x].a < q[y].a
+        }
+
+        if q[x].b != q[y].b {
+            return q[x].b < q[y].b
+        }
+
+        return q[x].c < q[y].c
+    })
+
+    k = 1
+    for i := 2; i <= n; i++ {
+        if q[i].a == q[k].a && q[i].b == q[k].b && q[i].c == q[k].c {
+            q[k].cnt++
+        } else {
+            k++
+            q[k] = q[i]
+        }
+    }
+
+    mergeSort(1, k)
+
+    for i := 1; i <= k; i++ {
+        ans[q[i].res+q[i].cnt-1] += q[i].cnt
+    }
+
+    for i := 0; i < n; i++ {
+        fmt.Println(ans[i])
+    }
+}