JAVA

Find Minimum in Rotated Sorted Array

// https://leetcode.com/problems/find-minimum-in-rotated-sorted-array
// assuming Array has no duplicates
class Solution {
    public int findMin(int[] nums) {
        int start = 0;
        int end  = nums.length-1;
        
        while (start < end){
            int mid = start + (end-start)/2;
            if (nums[mid] > nums[end]) start = mid+1;
            if (nums[mid] < nums[end]) end = mid;
        }
        return nums[start];
    }
}

Find minimum element in a sorted and rotated array

// Java program to find minimum element in a sorted and
// rotated array
import java.io.*;
import java.lang.*;
import java.util.*;
 
class Minimum {
    static int findMin(int arr[], int low, int high)
    {
        // This condition is needed to handle the case when
        // array is not rotated at all
        if (high < low)
            return arr[0];
 
        // If there is only one element left
        if (high == low)
            return arr[low];
 
        // Find mid
        int mid
            = low + (high - low) / 2; /*(low + high)/2;*/
 
        // Check if element (mid+1) is minimum element.
        // Consider the cases like {3, 4, 5, 1, 2}
        if (mid < high && arr[mid + 1] < arr[mid])
            return arr[mid + 1];
 
        // Check if mid itself is minimum element
        if (mid > low && arr[mid] < arr[mid - 1])
            return arr[mid];
 
        // Decide whether we need to go to left half or
        // right half
        if (arr[high] > arr[mid])
            return findMin(arr, low, mid - 1);
        return findMin(arr, mid + 1, high);
    }
 
    // Driver Program
    public static void main(String[] args)
    {
        int arr1[] = { 5, 6, 1, 2, 3, 4 };
        int n1 = arr1.length;
        System.out.println("The minimum element is "
                           + findMin(arr1, 0, n1 - 1));
 
        int arr2[] = { 1, 2, 3, 4 };
        int n2 = arr2.length;
        System.out.println("The minimum element is "
                           + findMin(arr2, 0, n2 - 1));
 
        int arr3[] = { 1 };
        int n3 = arr3.length;
        System.out.println("The minimum element is "
                           + findMin(arr3, 0, n3 - 1));
 
        int arr4[] = { 1, 2 };
        int n4 = arr4.length;
        System.out.println("The minimum element is "
                           + findMin(arr4, 0, n4 - 1));
 
        int arr5[] = { 2, 1 };
        int n5 = arr5.length;
        System.out.println("The minimum element is "
                           + findMin(arr5, 0, n5 - 1));
 
        int arr6[] = { 5, 6, 7, 1, 2, 3, 4 };
        int n6 = arr6.length;
        System.out.println("The minimum element is "
                           + findMin(arr6, 0, n6 - 1));
 
        int arr7[] = { 1, 2, 3, 4, 5, 6, 7 };
        int n7 = arr7.length;
        System.out.println("The minimum element is "
                           + findMin(arr7, 0, n7 - 1));
 
        int arr8[] = { 2, 3, 4, 5, 6, 7, 8, 1 };
        int n8 = arr8.length;
        System.out.println("The minimum element is "
                           + findMin(arr8, 0, n8 - 1));
 
        int arr9[] = { 3, 4, 5, 1, 2 };
        int n9 = arr9.length;
        System.out.println("The minimum element is "
                           + findMin(arr9, 0, n9 - 1));
    }
}