Find the row with maximum number of 1s

// Online C++ compiler to run C++ program online
#include <iostream>
#include<bits/stdc++.h>
#include<math.h>
using namespace std;
#define r 4
#define c 4
int first(bool 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;
}
int max1(bool mat[r][c])
{
    int i, index;
    int max_row=0;
    int max = first(mat[0],0,c-1);
    //cout<<max;
    for(i=1;i<r;i++)
    {
        if(max!=-1&&mat[i][c-max-1]==1){
            index= first(mat[i],0,c-max);
            if(index!=-1&&c-index>max){
                max =c-index;
                max_row=i;
                
            }
        }
        else {
            max=first(mat[i],0,c-1);
        }
}
return max_row;
}
int main()
{
     bool mat[r][c] = { {0, 0, 0, 1},
                    {0, 1, 1, 1},
                    {1, 1, 1, 1},
                    {0, 0, 0, 0}};
 
    cout << "Index of row with maximum 1s is " << max1(mat);
 
    return 0;
}