Algorithm to Count the Number of Possible Triangles
To count the number of possible triangles in a JavaScript array, we’ll follow these steps:
- To simplify the computations, sort the array ascending.
- Set up a variable to hold the number of triangles.
- Choose one side length to serve as a fixed base by iterating across the array.
- To identify pairs of sides (a, b) that meet the triangle inequality condition: a + b > base, use the two-pointer strategy.
- Increment the count of triangles with each valid combination of sides found.
- Continue the process until all possible combinations are checked.
Example: This example shows the use of the above-explained approach.
Javascript
// Function to Count all the // possible number of triangle function PossibleNumberOfTriangles(arr, n) { // Initialize count variable C to // count the number of triangles let C = 0; // The three loops will select 3 // different values from the array for (let i = 0; i < n; i++) { for (let j = i + 1; j < n; j++) { for (let k = j + 1; k < n; k++) { // This loop check for triangle property // Check Sum of two side is greater // than third side if ( arr[i] + arr[j] > arr[k] && arr[i] + arr[k] > arr[j] && arr[k] + arr[j] > arr[i] ) { C++; } } } } return C; } // Driver Code const arr = [2, 3, 4, 5, 8, 9]; const length = arr.length; console.log( "Total number of possible triangles are: " + PossibleNumberOfTriangles(arr, length) ); |
Output
Total number of possible triangles are: 8
JavaScript Program to Count the Number of Possible Triangles in Array
Triangles are basic geometric figures with three sides and three angles. Finding the number of triangles that can be created from a given set of side lengths is a frequent challenge in computational programming. In this article, we’ll see how to use a JavaScript array to calculate the total number of triangles that could exist. Before we proceed, we will understand the prerequisites for a legitimate triangle and offer a methodical solution to this issue.