Add examples for second laregst element in an array

Author: gauravkukade

java-programs/second-largest-element-in-an-array/SecondLargestElementInArray.java

@@ -0,0 +1,40 @@
+package com.coderolls.JavaPrograms.second_largest;
+/**
+ * A Java program to find the second largest number in an array 
+ * by iterating over an array using for loop.
+ * 
+ * @author coderolls.com
+ */
+public class SecondLargestElementInArray {
+
+	public static void main(String[] args) {
+		int[] arr = {2, 5, 9, 8, 11, 18, 13};
+		
+		int secondLargest = getSecondLargest(arr);
+		System.out.println("The second largest element in an array 'arr' is :"+ secondLargest);
+	}
+
+	private static int getSecondLargest(int[] arr) {
+		int n =arr.length;
+		int largest =arr[0];
+		int secondLargest = -1;
+		
+		for(int i=0; i<n; i++) {
+			if(arr[i]>largest) {
+				//if you found the new largest,
+				//copy current largest to second largest and
+				//copy current element arr[i] to largest
+				secondLargest = largest;
+				largest = arr[i];
+			}else if(arr[i]!=largest) {
+				// if the current element arr[i] is not the largest and 
+				// still larger than the current secondLargest
+				// then copy it to secondLargest
+				if(arr[i]>secondLargest) {
+					secondLargest = arr[i];
+				}
+			}
+		}
+		return secondLargest;
+	}
+}

java-programs/second-largest-element-in-an-array/SecondLargestElementInArrayUsingArrays.java

@@ -0,0 +1,25 @@
+package com.coderolls.JavaPrograms.second_largest;
+
+import java.util.Arrays;
+
+/**
+ * A Java program to find the second largest number in an array 
+ * using Arrays.sort() method.
+ * 
+ * @author coderolls.com
+ */
+public class SecondLargestElementInArrayUsingArrays {
+
+	public static void main(String[] args) {
+		int[] arr = {2, 5, 9, 8, 11, 18, 13};
+		
+		int secondLargest = getSecondLargest(arr);
+		System.out.println("The second largest element in an array 'arr' is using Arrays.sort() :"+ secondLargest);
+	}
+
+	private static int getSecondLargest(int[] arr) {
+		Arrays.sort(arr);
+		// return second largest, so length-2
+		return arr[arr.length-2];
+	}
+}