From 1394f09d277e96083e924c43fd3476beb6ede4a5 Mon Sep 17 00:00:00 2001
From: anebz <ane.berasategi@gmail.com>
Date: Sat, 30 Mar 2019 14:35:37 +0100
Subject: [PATCH] Revert "Revert "1.5. levenshtein distance""

This reverts commit 295fb6c179172a04bf624aaebab69e7de2c77891.
---
 .../1.5. levenshtein.java                     | 43 +++++++++++++++++++
 1 file changed, 43 insertions(+)
 create mode 100644 Chapter 1 Arrays and strings/1.5. levenshtein.java

diff --git a/Chapter 1 Arrays and strings/1.5. levenshtein.java b/Chapter 1 Arrays and strings/1.5. levenshtein.java
new file mode 100644
index 0000000..f13b421
--- /dev/null
+++ b/Chapter 1 Arrays and strings/1.5. levenshtein.java	
@@ -0,0 +1,43 @@
+public class levenshtein {	
+    public static boolean oneEditAway(String first, String second) {
+		/* Length checks. */
+		if (Math.abs(first.length() - second.length()) > 1) {
+			return false;
+		}
+		
+		/* Get shorter and longer string.*/
+		String s1 = first.length() < second.length() ? first : second;
+		String s2 = first.length() < second.length() ? second : first;
+
+		int index1 = 0;
+		int index2 = 0;
+        boolean foundDifference = false;
+        
+		while (index2 < s2.length() && index1 < s1.length()) {
+			if (s1.charAt(index1) != s2.charAt(index2)) {
+				/* Ensure that this is the first difference found.*/
+				if (foundDifference) return false;
+				foundDifference = true;
+				if (s1.length() == s2.length()) { // On replace, move shorter pointer
+					index1++;
+				}
+			} else {
+				index1++; // If matching, move shorter pointer 
+			}
+			index2++; // Always move pointer for longer string 
+		}
+		return true;
+	}
+	
+	public static void main(String[] args) {
+		String a = "palee";
+		String b = "pale";
+		boolean isOneEdit1 = oneEditAway(a, b);
+		System.out.println(a + ", " + b + ": " + isOneEdit1);
+
+		String c = "pale";
+		String d = "pkle";
+		boolean isOneEdit2 = oneEditAway(c, d);
+		System.out.println(c + ", " + d + ": " + isOneEdit2);
+	}
+}
\ No newline at end of file