[2400][2A] CF12D 三维偏序 树状数组

main/1-99/12D.go

@@ -0,0 +1,52 @@
+package main
+
+import (
+	"bufio"
+	. "fmt"
+	"io"
+	"sort"
+)
+
+// https://space.bilibili.com/206214
+func cf12D(_r io.Reader, out io.Writer) {
+	in := bufio.NewReader(_r)
+	var n, ans int
+	Fscan(in, &n)
+	a := make([]struct{ x, y, z int }, n)
+	for i := range a {
+		Fscan(in, &a[i].x)
+	}
+	sy := make([]int, n)
+	for i := range a {
+		Fscan(in, &a[i].y)
+		sy[i] = a[i].y
+	}
+	for i := range a {
+		Fscan(in, &a[i].z)
+	}
+	sort.Slice(a, func(i, j int) bool { return a[i].x > a[j].x })
+	sort.Ints(sy)
+
+	t := make([]int, n+1)
+	for i := 0; i < n; {
+		st := i
+		v := a[st].x
+		for ; i < n && a[i].x == v; i++ {
+			a[i].y = n - sort.SearchInts(sy, a[i].y) // 要维护的是后缀最大值
+			for j := a[i].y - 1; j > 0; j &= j - 1 {
+				if t[j] > a[i].z {
+					ans++
+					break
+				}
+			}
+		}
+		for ; st < i; st++ {
+			for j := a[st].y; j <= n; j += j & -j {
+				t[j] = max(t[j], a[st].z)
+			}
+		}
+	}
+	Fprint(out, ans)
+}
+
+//func main() { cf12D(os.Stdin, os.Stdout) }

main/1-99/12D_test.go

@@ -0,0 +1,29 @@
+// Generated by copypasta/template/generator_test.go
+package main
+
+import (
+	"github.com/EndlessCheng/codeforces-go/main/testutil"
+	"testing"
+)
+
+// https://codeforces.com/problemset/problem/12/D
+// https://codeforces.com/problemset/status/12/problem/D
+func Test_cf12D(t *testing.T) {
+	testCases := [][2]string{
+		{
+			`3
+1 4 2
+4 3 2
+2 5 3`,
+			`1`,
+		},
+		{
+			`5
+2 8 10 0 7
+7 7 3 0 10
+2 8 3 2 2`,
+			`1`,
+		},
+	}
+	testutil.AssertEqualStringCase(t, testCases, 0, cf12D)
+}