JavaScript: Find the kth greatest element of a given array of integers

Last update on May 30 2022 10:00:20 (UTC/GMT +8 hours)

JavaScript Basic: Exercise-90 with Solution

Write a JavaScript program to find the kth greatest element of a given array of integers.

Pictorial Presentation:

JavaScript: Find the kth greatest element of a given array of integers.

Sample Solution:

HTML Code:

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>Find the kth greatest element of a given array of integers.</title>
</head>
<body>

</body>
</html>

JavaScript Code:

function Kth_greatest_in_array(arr, k) {

  for (var i = 0; i < k; i++) {
    var max_index = i,
      tmp = arr[i];

    for (var j = i + 1; j < arr.length; j++) {
      if (arr[j] > arr[max_index]) {
        max_index = j;
      }
    }

    arr[i] = arr[max_index];
    arr[max_index] = tmp;
  }

  return arr[k - 1];
}

console.log(Kth_greatest_in_array([1,2,6,4,5], 3))
console.log(Kth_greatest_in_array([-10,-25,-47,-36,0], 1))

Sample Output:

4
0

Flowchart:

ES6 Version:

function Kth_greatest_in_array(arr, k) {

  for (let i = 0; i < k; i++) {
    let max_index = i;
    const tmp = arr[i];

    for (let j = i + 1; j < arr.length; j++) {
      if (arr[j] > arr[max_index]) {
        max_index = j;
      }
    }

    arr[i] = arr[max_index];
    arr[max_index] = tmp;
  }

  return arr[k - 1];
}

console.log(Kth_greatest_in_array([1,2,6,4,5], 3))
console.log(Kth_greatest_in_array([-10,-25,-47,-36,0], 1))

Live Demo:

See the Pen javascript-basic-exercise-90 by w3resource (@w3resource) on CodePen.

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Previous: Write a JavaScript program to check whether it is possible to replace $ in a given expression x $ y = z with one of the four signs +, -, * or / to obtain a correct expression.
Next: Write a JavaScript program to find the maximum possible sum of some of its k consecutive numbers (numbers that follow each other in order.) of a given array of positive integers.

JavaScript: Tips of the Day

How to insert an item into an array at a specific index (JavaScript)?

What you want is the splice function on the native array object.

arr.splice(index, 0, item); will insert item into arr at the specified index (deleting 0 items first, that is, it's just an insert). In this example we will create an array and add an element to it into index 2:

var arr = []; arr[0] = "Jani"; arr[1] = "Hege"; arr[2] = "Stale"; arr[3] = "Kai Jim"; arr[4] = "Borge"; console.log(arr.join()); arr.splice(2, 0, "Lene"); console.log(arr.join());

Ref: https://bit.ly/2BXbp04