How to use Set Intersection In Javascript
This method involves comparing sets to find common elements among rows in a matrix. It’s a straightforward method that simplifies the process of identifying shared elements efficiently.
Example: To demonsrtate finding the common elements in all rows of agiven matrix using JavaScript set intersection method.
function findCommonElements(matrix)
{
if (matrix.length === 0) return [];
// Convert first row to set
let commonSet = new Set(matrix[0]);
// Intersect with sets of subsequent rows
for (let i = 1; i < matrix.length; i++)
{
commonSet = new Set(matrix[i]
.filter(x => commonSet.has(x)));
}
return Array
.from(commonSet);
}
const matrix1 = [
[1, 2, 3],
[2, 3, 4],
[3, 4, 5]
];
console.log(findCommonElements(matrix1));
const matrix2 =
[
[1, 2, 3],
[4, 5, 6],
[7, 8, 9]
];
console.log(findCommonElements(matrix2));
Output
[ 3 ] []
Time Complexity: O(n*m), where n is the number of rows and m is the average number of elements in each row.
Space Complexity: O(m), where m is the average number of elements in each row.
Find Common Elements in all Rows of a Given Matrix using JavaScript
Matrix manipulation takes place in a large number of applications, and the detection of shared elements among rows is one of the common challenges.
Example:
Input : [1, 2, 3],
[2, 3, 4],
[3, 4, 5]
Output: [3]
Input : [1, 2, 3],
[4, 5, 6],
[7, 8, 9]
Output: [ ]
There are the following approaches for finding the common elements in all rows of a given matrix using JavaScript which are as follows:
Table of Content
- Using Set Intersection
- Sorting and Comparing