C++ Program to Check if it is possible to make array increasing or decreasing by rotating the array

// C++ implementation of the approach
#include <bits/stdc++.h>
using namespace std;

// Function that returns true if the array
// can be made increasing or decreasing
// after rotating it in any direction
bool isPossible(int a[], int n)
{
    // If size of the array is less than 3
    if (n <= 2)
        return true;

    int flag = 0;
    // Check if the array is already decreasing
    for (int i = 0; i < n - 2; i++) {
        if (!(a[i] > a[i + 1] and a[i + 1] > a[i + 2])) {
            flag = 1;
            break;
        }
    }

    // If the array is already decreasing
    if (flag == 0)
        return true;

    flag = 0;
    // Check if the array is already increasing
    for (int i = 0; i < n - 2; i++) {
        if (!(a[i] < a[i + 1] and a[i + 1] < a[i + 2])) {
            flag = 1;
            break;
        }
    }

    // If the array is already increasing
    if (flag == 0)
        return true;

    // Find the indices of the minimum
    // and the maximum value
    int val1 = INT_MAX, mini = -1, val2 = INT_MIN, maxi;
    for (int i = 0; i < n; i++) {
        if (a[i] < val1) {
            mini = i;
            val1 = a[i];
        }
        if (a[i] > val2) {
            maxi = i;
            val2 = a[i];
        }
    }

    flag = 1;
    // Check if we can make array increasing
    for (int i = 0; i < maxi; i++) {
        if (a[i] > a[i + 1]) {
            flag = 0;
            break;
        }
    }

    // If the array is increasing upto max index
    // and minimum element is right to maximum
    if (flag == 1 and maxi + 1 == mini) {
        flag = 1;
        // Check if array increasing again or not
        for (int i = mini; i < n - 1; i++) {
            if (a[i] > a[i + 1]) {
                flag = 0;
                break;
            }
        }
        if (flag == 1)
            return true;
    }

    flag = 1;
    // Check if we can make array decreasing
    for (int i = 0; i < mini; i++) {
        if (a[i] < a[i + 1]) {
            flag = 0;
            break;
        }
    }

    // If the array is decreasing upto min index
    // and minimum element is left to maximum
    if (flag == 1 and maxi - 1 == mini) {
        flag = 1;

        // Check if array decreasing again or not
        for (int i = maxi; i < n - 1; i++) {
            if (a[i] < a[i + 1]) {
                flag = 0;
                break;
            }
        }
        if (flag == 1)
            return true;
    }

    // If it is not possible to make the
    // array increasing or decreasing
    return false;
}

// Driver code
int main()
{
    int a[] = { 4, 5, 6, 2, 3 };
    int n = sizeof(a) / sizeof(a[0]);

    if (isPossible(a, n))
        cout << "Yes";
    else
        cout << "No";

    return 0;
}