maximum number of 1s.java

import java.io.*;
 
class GFG {
    static int R = 4, C = 4;
    // Function to find the index of first index
    // of 1 in a boolean array arr[]
    static int first(int arr[], int low, int high)
    {
        if (high >= low) {
            // Get the middle index
            int mid = low + (high - low) / 2;
 
            // Check if the element at middle index is first 1
            if ((mid == 0 || (arr[mid - 1] == 0)) && arr[mid] == 1)
                return mid;
 
            // If the element is 0, recur for right side
            else if (arr[mid] == 0)
                return first(arr, (mid + 1), high);
                 
            // If element is not first 1, recur for left side
            else
                return first(arr, low, (mid - 1));
        }
        return -1;
    }
 
    // Function that returns index of row
    // with maximum number of 1s.
    static int rowWithMax1s(int mat[][])
    {
        // Initialize max values
        int max_row_index = 0, max = -1;
 
        // Traverse for each row and count number of
        // 1s by finding the index of first 1
        int i, index;
        for (i = 0; i < R; i++) {
            index = first(mat[i], 0, C - 1);
            if (index != -1 && C - index > max) {
                max = C - index;
                max_row_index = i;
            }
        }
 
        return max_row_index;
    }
    // Driver Code
    public static void main(String[] args)
    {
        int mat[][] = { { 0, 0, 0, 1 },
                        { 0, 1, 1, 1 },
                        { 1, 1, 1, 1 },
                        { 0, 0, 0, 0 } };
        System.out.println("Index of row with maximum 1s is "
                                            + rowWithMax1s(mat));
    }
}