# Algorithm problem flip array

Given a n integer array a with length N, the elements are different. Ask if there is such a fragment in the array. Only turning the fragment over can make the whole array in ascending order. Where array fragment [l,r] represents sequence a[l], a[l+1],   a[r]. The original array is
a[1], a[2], ..., a[l-2], a[l-1], a[l], a[l+1], ..., a[r-1], a[r], a[r+1], a[r+2], ..., a[n-1], a[n]，
The array after reversing the fragment [l,r] is
a[1], a[2], ..., a[l-2], a[l-1], a[r], a[r-1], ..., a[l+1], a[l], a[r+1], a[r+2], ..., a[n-1], a[n].

input sample input
The first row of data is an integer: n (1 ≤ n ≤ 105), indicating the array length. 4
The second row of data is n integers a[1], a[2] , a[n] (1≤a[i]≤109). 2 1 3 4
output sample output
Output "yes" if it exists; otherwise, output "no" without quotation marks. yes
using System;

namespace Practice
{
class Program
{
static void Main(string[] args)
{
string[] temp = input.Split(' ');
int[] num = new int[count];
bool output = false;
for (int i = 0; i < count; i++)
{
num[i] = Convert.ToInt32(temp[i]);
}
//Pick array fragment

for (int i = 0; i < count; i++)
{
for (int  k = count; i < k; k--)
{

int[] num3 = new int[count];
for (int j = 0; j < count; j++)
num3[j] = num[j];

Array.Reverse(num3,i,k-i);

bool flag = true;
for (int j = 0; j < count-1; j++)
{
if (num3[j] > num3[j + 1])
{
flag = false;
break;
}

}
if (flag) output = true;

}
}

if (output) Console.WriteLine("yes");
else Console.WriteLine("no");