Given an array of pairs of integers. The task is to sort the array with respect to the second element of the pair.
Examples:
Input: [(1, 2), (3, 5), (2, 6), (1, 7)]
Output: [(1, 2), (3, 5), (2, 6), (1, 7)]Input: [(10, 20), (20, 30), (5, 6), (2, 5)]
Output: [(2, 5), (5, 6), (10, 20), (20, 30)]
Approach:
- Store the pairs in an array using a user-defined Pair class.
- Override the comparator method to sort the array according to the second element.
- Sort the array according to the second element.
Below is the implementation of the above approach:
Java
// Java code to sort the array// according to second element// Importing required classesimport java.util.Arrays;import java.util.Comparator;// User defined Pair classclass Pair { int x; int y; // Constructor public Pair(int x, int y) { this.x = x; this.y = y; } // Overriding toString method // for beautiful printing of pairs @Override public String toString() { return "(" + x + ", " + y + ')'; }}// class to define user defined comparatorclass ArrayOfPairsSorter { static void sort(Pair[] arr) { Comparator<Pair> comparator = new Comparator<>() { @Override public int compare(Pair p1, Pair p2) { return p1.y - p2.y; // To compare the first element // just // change the variable from p1.y // - p2.y to p1.x-p2.x. } }; Arrays.sort(arr, comparator); }}// Main classclass GFG { // Main driver method public static void main(String[] args) { // Array of 5 Pairs Pair[] arr = new Pair[5]; arr[0] = new Pair(10, 20); arr[1] = new Pair(1, 2); arr[2] = new Pair(3, 1); arr[3] = new Pair(10, 8); arr[4] = new Pair(4, 3); ArrayOfPairsSorter.sort(arr); System.out.println(Arrays.toString(arr)); }} |
Output:
[(3, 1), (1, 2), (4, 3), (10, 8), (10, 20)]
