Find the position of the last removed element from the array - GeeksforGeeks

03 May, 2021
Given an array of size and an integer . Perform the following operations on the given array: 
If a[i] > M then push a[i] – M to end of the array, otherwise remove it from the array.Perform the first operation while the array is non-empty.
If a[i] > M then push a[i] – M to end of the array, otherwise remove it from the array.
Perform the first operation while the array is non-empty.
The task is to find the original position of the element which gets removed last. 
Examples:  
Input: arr[] = {4, 3}, M = 2 Output: 2 Remove 4 from the array and the array becomes {3, 2} with original positions {2, 1} Remove 3 from the array and the array becomes {2, 1} with original positions {1, 2} Remove 2 from the array and the array becomes {1} with original positions {2} So, 2nd positioned element is the last to be removed from the array.
Input: arr[] = {2, 5, 4}, M = 2 Output: 2  
The idea is to observe the last element which will be removed from the array. It can by easily said that the element to be removed last will be the element which can be subtracted max number of times by among all elements of the array. That is, the element with maximum value of ceil(a[i] / M).
So, the task now reduces to find the index of the element in the array with maximum value of ceil(a[i] / M).
Below is the implementation of the above approach:  
C++
Java
Python3
C#
PHP
Javascript
// C++ program to find the position of the// last removed element from the array#include <bits/stdc++.h>using namespace std; // Function to find the original position// of the element which will be// removed lastint getPosition(int a[], int n, int m){    // take ceil of every number    for (int i = 0; i < n; i++) {        a[i] = (a[i] / m + (a[i] % m != 0));    }     int ans = -1, max = -1;    for (int i = n - 1; i >= 0; i--) {        if (max < a[i]) {            max = a[i];            ans = i;        }    }     // Since position is index+1    return ans + 1;} // Driver codeint main(){    int a[] = { 2, 5, 4 };     int n = sizeof(a) / sizeof(a[0]);     int m = 2;     cout << getPosition(a, n, m);     return 0;}
// Java program to find the position of the// last removed element from the arrayimport java.util.*; class solution{ // Function to find the original position// of the element which will be// removed last static int getPosition(int a[], int n, int m){    // take ceil of every number    for (int i = 0; i < n; i++) {        a[i] = (a[i] / m + (a[i] % m));    }     int ans = -1, max = -1;    for (int i = n - 1; i >= 0; i--) {        if (max < a[i]) {            max = a[i];            ans = i;        }    }     // Since position is index+1    return ans + 1;} // Driver codepublic static void main(String args[]){    int a[] = { 2, 5, 4 };     int n = a.length;     int m = 2; System.out.println(getPosition(a, n, m)); } }//This code is contributed by// Surendra_Gangwar
# Python3 program to find the position of# the last removed element from the arrayimport math as mt # Function to find the original# position of the element which# will be removed lastdef getPosition(a, n, m):     # take ceil of every number    for i in range(n):        a[i] = (a[i] // m +               (a[i] % m != 0))         ans, maxx = -1,-1    for i in range(n - 1, -1, -1):        if (maxx < a[i]):            maxx = a[i]            ans = i                 # Since position is index+1    return ans + 1 # Driver codea = [2, 5, 4] n = len(a) m = 2 print(getPosition(a, n, m)) # This is contributed by Mohit kumar 29
// C# program to find the position of the// last removed element from the arrayusing System; class GFG{     // Function to find the original// position of the element which// will be removed laststatic int getPosition(int []a,                       int n, int m){    // take ceil of every number    for (int i = 0; i < n; i++)    {        a[i] = (a[i] / m + (a[i] % m));    }     int ans = -1, max = -1;    for (int i = n - 1; i >= 0; i--)    {        if (max < a[i])        {            max = a[i];            ans = i;        }    }     // Since position is index+1    return ans + 1;} // Driver codestatic public void Main (){    int []a = { 2, 5, 4 };    int n = a.Length;    int m = 2;    Console.WriteLine(getPosition(a, n, m));}} // This code is contributed by ajit
<?php// PHP program to find the position of the// last removed element from the array // Function to find the original// position of the element which// will be removed lastfunction getPosition($a, $n, $m){    // take ceil of every number    for ( $i = 0; $i < $n; $i++)    {        $a[$i] = ($a[$i] / $m +                 ($a[$i] % $m != 0));    }     $ans = -1;    $max = -1;    for ($i = $n - 1; $i >= 0; $i--)    {        if ($max < $a[$i])        {            $max = $a[$i];            $ans = $i;        }    }     // Since position is index+1    return $ans + 1;} // Driver code$a = array( 2, 5, 4 );$n = sizeof($a);$m = 2; echo getPosition($a, $n, $m); // This code is contributed by jit_t?>
<script> // Javascript program to find the position// of the last removed element from the array // Function to find the original// position of the element which// will be removed lastfunction getPosition(a, n, m){         // Take ceil of every number    for(let i = 0; i < n; i++)    {        a[i] = (a[i] / m + (a[i] % m));    }     let ans = -1, max = -1;    for(let i = n - 1; i >= 0; i--)    {        if (max < a[i])        {            max = a[i];            ans = i;        }    }     // Since position is index+1    return ans + 1;} // Driver codelet a = [ 2, 5, 4 ];let n = a.length;let m = 2; document.write(getPosition(a, n, m)); // This code is contributed by rameshtravel07 </script>
2
 
SURENDRA_GANGWAR
jit_t
mohit kumar 29
rameshtravel07
number-theory
Arrays
Competitive Programming
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