Finding Maximum Element of Java Vector

Vector implements a dynamic array that means it can grow or shrink as required. Like an array, it contains components that can be accessed using an integer index. We know two ways for declaring array i.e. either with a fixed size of array or size enter as per the demand of the user according to which array is allocated in memory. 

int Array_name[Fixed_size] ;

int array_name[variable_size] ;

In both ways, we land up wasting memory so, in order to properly utilize memory optimization, Vectors were introduced. We have to find out the maximum element in the given Java vector.

Examples:

Input: [1,2,3,4,5]
Output: 5
Input: [88,23,76,90,56]
Output: 90

Approach 1: Using a Predefined Function

• To find the minimum element of a given vector we use the java.util.Collections.max() method.
• This directly finds the maximum value in the vector.

Java

// Java program to find
// maximum element in java vector

import java.io.*;
import java.util.Collections;
import java.util.Vector;
public class GFG {

    public static void main(String args[])

        Vector<Integer> vec = new Vector<Integer>();

        vec.add(1);
        vec.add(2);
        vec.add(3);
        vec.add(4);
        vec.add(5);

        System.out.println("Vector elements: " + vec);

        System.out.println("The maximum element of the Vector is: "
         + Collections.max(vec));
    }
 }

Output

Vector elements: [1, 2, 3, 4, 5]
The maximum element of the Vector is: 5

Worst Case Time Complexity: O(n) where n is the number of elements present in the vector.

Approach 2: Comparing each element present in Vector

• First, we will initialize a vector let’s say v, then we will store values in that vector.
• Next, we will take a variable, let us say maxNumber and assign the maximum value possible.
• Traverse till the end of vector and compare each element of a vector with maxNumber.
• If the element present in the vector is greater than maxNumber, then update maxNumber to that value.
• Print maxNumber.

Java

// Java program to find largest element
// present in Vector via comparison

import java.io.*;

// Importing Vector Class
import java.util.Vector;

// Importing Iterator Class
import java.util.Iterator;

class GFG {

    // Main Method
    public static void main(String[] args)
    {
        // initializing vector of Integer type
        Vector<Integer> v = new Vector<Integer>();

        // Adding elements in vector
        v.add(10);
        v.add(20);
        v.add(30);
        v.add(40);
        v.add(50);

        // Assigning min value possible
        int maxValue = Integer.MIN_VALUE;

        // Creating an iterator to traverse through vector
        // in the beginning itr will point to index just
        // before first element
        Iterator itr = v.iterator();

        // See if there is any next element
        while (itr.hasNext())
        {
            // Moving iterator to next element
            int element = (Integer)itr.next();

            // Comparing if element is larger than maxValue
            if (element > maxValue)
            {
                // Update maxValue
                maxValue = element;
            }
        }

        // Print maxVaue
        System.out.println( "The largest element present in Vector is : "
            + maxValue);
    }
}

Output

The largest element present in Vector is : 50

Time Complexity: O(n) where n is the number of elements present in the vector.