Question

How to find the indexes of the first and last occurrences of an element in array in Java

Answer 1

public class MyClass {
    private static void findFirstAndLastIndex(int[] array, int element) {
	    int first = -1, last = -1;
	    int size = array.length;

	    for (int i = 0; i < size; i++) {
		    if (array[i] != element) {
			    continue;
		    }
		    
		    if (first == -1) {
			    first = i;
		    }
		    
		    last = i;
	    }

	    if (first != -1) {
    		System.out.println("First Occurrence = " + first);
    		System.out.println("Last Occurrence = " + last);
    	}
    	else {
    		System.out.print("Not Found");
    	}
    }
    public static void main(String args[]) {
        int[] array = {3, 2, 4, 7, 3, 0, 9, 8, 7, 7, 12, 18};

	    int element = 7;

	    findFirstAndLastIndex(array, element);
    }
}





/*
run:
  
First Occurrence = 3
Last Occurrence = 9
  
*/

 

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