Q1.We are given a row-wise sorted matrix of size rc, we need to find the median of the matrix given. It is assumed that rc is always odd.

Examples:

Input:

1 3 5

2 6 8

3 6 9

Output:

Median is 5

Given this solution!!

public int findMedian(int arr[][]) {
        int m = arr.length;
        int n = arr[0].length;
        int elements[] = new int[m * n];
        int count = 0;
        for (int i = 0; i < m; i++) {
            for (int j = 0; j < n; j++) {
                elements[count] = arr[i][j];
                count++;
            }
        }
        Arrays.sort(elements);  // uses dual pivot quick sort internally
        return elements[elements.length / 2];
       }

Interviewer is looking for some more optimize solution. Once the interview get over i solve this problem using heap :

    public int findMedian(int arr[][]) {
    PriorityQueue<Integer> maxHeap = new PriorityQueue<>(Collections.reverseOrder());
    int m = arr.length;
    int n = arr[0].length;

    int medianIndex = (m*n)/2+1;

    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            maxHeap.add(arr[i][j]);
            if(maxHeap.size()>medianIndex){
                maxHeap.poll();
            }
        }
    }
    return maxHeap.peek();
}
	
	
	

Problem 2:

A valid IP address consists of exactly four integers separated by single dots. Each integer is between 0 and 255 (inclusive) and cannot have leading zeros.

For example, "0.1.2.201" and "192.168.1.1" are valid IP addresses, but "0.011.255.245", "192.168.1.312" and "192.168@1.1" are invalid IP addresses.
Given a string s containing only digits, return all possible valid IP addresses that can be formed by inserting dots into s. You are not allowed to reorder or remove any digits in s. You may return the valid IP addresses in any order.

Example 1:

Input: s = "25525511135"

Output: ["255.255.11.135","255.255.111.35"]

Input: s = "101023"

Output: ["1.0.10.23","1.0.102.3","10.1.0.23","10.10.2.3","101.0.2.3"]

Not able to solve this problem!!

I have seen lots of rejection in last couples of days ....:( :( but keep trying ....