给定一个数组的n个长度，问题是我们必须找到给定数组中最短的无序{既不增加也不减少}子数组的长度。
例子：
Input : n = 5
7 9 10 8 11
Output : 3
Explanation : 9 10 8 unordered sub array.
Input : n = 5
1 2 3 4 5
Output : 0
Explanation : Array is in increasing order.这个想法基于以下事实：最短子数组的大小为0或3。我们必须检查数组元素是增加还是减少，如果所有数组元素都在增加或减少，则最短子数组的长度为0，而且，如果数组元素中的任何一个都不跟随递增或递减，则其最短长度为3。
C++
// CPP program to find shortest subarray which is
// unsorted.
#include
using namespace std;
// bool function for checking an array elements
// are in increasing.
bool increasing(int a[], int n)
{
for (int i = 0; i < n - 1; i++)
if (a[i] >= a[i + 1])
return false;
return true;
}
// bool function for checking an array
// elements are in decreasing.
bool decreasing(int a[], int n)
{
for (int i = 0; i < n - 1; i++)
if (a[i] < a[i + 1])
return false;
return true;
}
int shortestUnsorted(int a[], int n)
{
// increasing and decreasing are two functions.
// if function return true value then print
// 0 otherwise 3.
if (increasing(a, n) == true ||
decreasing(a, n) == true)
return 0;
else
return 3;
}
// Driver code
int main()
{
int ar[] = { 7, 9, 10, 8, 11 };
int n = sizeof(ar) / sizeof(ar[0]);
cout << shortestUnsorted(ar, n);
return 0;
} Java
// JAVA program to find shortest subarray which is
// unsorted.
import java.util.*;
import java.io.*;
class GFG {
// boolean function to check array elements
// are in increasing order or not
public static boolean increasing(int a[],int n)
{
for (int i = 0; i < n - 1; i++)
if (a[i] >= a[i + 1])
return false;
return true;
}
// boolean function to check array elements
// are in decreasing order or not
public static boolean decreasing(int arr[],int n)
{
for (int i = 0; i < n - 1; i++)
if (arr[i] < arr[i + 1])
return false;
return true;
}
public static int shortestUnsorted(int a[],int n)
{
// increasing and decreasing are two functions.
// if function return true value then print
// 0 otherwise 3.
if (increasing(a, n) == true ||
decreasing(a, n) == true)
return 0;
else
return 3;
}
// driver program
public static void main (String[] args) {
int ar[] = new int[]{7, 9, 10, 8, 11};
int n = ar.length;
System.out.println(shortestUnsorted(ar,n));
}
}
// This code is contributed by Akash Singh.Python3
# Python3 program to find shortest
# subarray which is unsorted
# Bool function for checking an array
# elements are in increasing
def increasing(a, n):
for i in range(0, n - 1):
if (a[i] >= a[i + 1]):
return False
return True
# Bool function for checking an array
# elements are in decreasing
def decreasing(a, n):
for i in range(0, n - 1):
if (a[i] < a[i + 1]):
return False
return True
def shortestUnsorted(a, n):
# increasing and decreasing are two functions.
# if function return True value then print
# 0 otherwise 3.
if (increasing(a, n) == True or
decreasing(a, n) == True):
return 0
else:
return 3
# Driver code
ar = [7, 9, 10, 8, 11]
n = len(ar)
print(shortestUnsorted(ar, n))
# This code is contributed by Smitha Dinesh Semwal.C#
// Program to find the shortest
// subarray which is unsorted.
using System;
class GFG {
// boolean function to check
// array elements are in the
// increasing order or not
public static bool increasing(int[] a, int n)
{
for (int i = 0; i < n - 1; i++)
if (a[i] >= a[i + 1])
return false;
return true;
}
// boolean function to check
// array elements are in the
// decreasing order or not
public static bool decreasing(int[] arr, int n)
{
for (int i = 0; i < n - 1; i++)
if (arr[i] < arr[i + 1])
return false;
return true;
}
public static int shortestUnsorted(int[] a, int n)
{
// increasing and decreasing are
// two functions. function return
// true value then print 0 else 3
if (increasing(a, n) == true ||
decreasing(a, n) == true)
return 0;
else
return 3;
}
// Driver program
public static void Main()
{
int[] ar = new int[] { 7, 9, 10, 8, 11 };
int n = ar.Length;
Console.WriteLine(shortestUnsorted(ar, n));
}
}
// This code is contributed by vt_m.PHP
= $a[$i + 1])
return false;
return true;
}
// bool function for checking an
// array elements are in decreasing.
function decreasing($a, $n)
{
for ($i = 0; $i < $n - 1; $i++)
if ($a[$i] < $a[$i + 1])
return false;
return true;
}
function shortestUnsorted($a, $n)
{
// increasing and decreasing are
// two functions. if function
// return true value then print
// 0 otherwise 3.
if (increasing($a, $n) == true ||
decreasing($a, $n) == true)
return 0;
else
return 3;
}
// Driver code
$ar = array( 7, 9, 10, 8, 11 );
$n = sizeof($ar);
echo shortestUnsorted($ar, $n);
// This code is contributed by
// nitin mittal.
?>Javascript
输出 ：
3