/
1585D.go
55 lines (51 loc) · 912 Bytes
/
1585D.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
package main
import (
"bufio"
. "fmt"
"io"
)
// github.com/EndlessCheng/codeforces-go
func CF1585D(_r io.Reader, _w io.Writer) {
in := bufio.NewReader(_r)
out := bufio.NewWriter(_w)
defer out.Flush()
var T, n int
for Fscan(in, &T); T > 0; T-- {
Fscan(in, &n)
a := make([]int, n+1)
p := make([]int, n+1)
eq := false
for i := 1; i <= n; i++ { // 注意 a 从 1 开始
Fscan(in, &a[i])
if p[a[i]] > 0 {
eq = true
}
p[a[i]] = i
}
if eq || n < 2 {
Fprintln(out, "YES")
continue
}
for i := 1; i < n-1; i++ {
if p[i] == i {
continue
}
x, y := p[i], i
z := n
if x == n {
z--
}
p[a[z]] = x
p[a[y]] = z
a[x] = a[z]
a[z] = a[y]
//a[x], a[y], a[z] = a[z], a[x], a[y]
}
if a[n-1] < a[n] { // 注意 a 从 1 开始
Fprintln(out, "YES")
} else {
Fprintln(out, "NO")
}
}
}
//func main() { CF1585D(os.Stdin, os.Stdout) }