findlocalminimum

Solution.java

public class Solution {


    static int findLocalMinimum(int[] a) {
        
        if (a[0] < a[1]) {
            return 0;
        }

        if (a[a.length - 1] < a[a.length - 2]) {
            return a.length - 1;
        }

        int s = 0;
        int count = 0;
        int e = a.length - 1;
        int mid = (s + e) / 2;
        while (s <= e) {
            count++;
            System.out.printf("s:%d e:%d m:%d\n", s, e, mid);
            System.out.printf("%d %d %d\n", a[s], a[e], a[mid]);
            System.out.println("Count:" + count);
            mid = s + (e - s) / 2;
            if ((a[mid] < a[mid + 1]) && (a[mid] < a[mid - 1])) {
                return mid;
            }
            if ((a[mid] < a[mid + 1]))
                e = mid - 1;
            else s = mid + 1;

        }
        
        return -1;
    }

    public static void main(String[] args) {
        int x[] = {9, 1, 2, 3, 4, 5, 3, 1, 2, 3, 4, 5, 9};
        System.out.println(findLocalMinimum(x));
    }
};