solves backspace string compare

Author: anishLearnsToCode

Diff for: README.md

@@ -227,7 +227,7 @@
 | 832 | [Flipping an Image](https://leetcode.com/problems/flipping-an-image) | [![Java](assets/java.png)](src/FlippingAnImage.java) |
 | 836 | [Rectangle Overlap](https://leetcode.com/problems/rectangle-overlap) | [![Java](assets/java.png)](src/RectangleOverlap.java) |
 | 840 | [Magic Squares in Grid](https://leetcode.com/problems/magic-squares-in-grid) | |
-| 844 | [Backspace String Compare](https://leetcode.com/problems/backspace-string-compare) | |
+| 844 | [Backspace String Compare](https://leetcode.com/problems/backspace-string-compare) | [![Java](assets/java.png)](src/BackspaceStringCompare.java) |
 | 849 | [Maximize Distance to Closest Person](https://leetcode.com/problems/maximize-distance-to-closest-person) | |
 | 852 | [Peak Index in Mountain Array](https://leetcode.com/problems/peak-index-in-a-mountain-array) | |
 | 859 | [Buddy Strings](https://leetcode.com/problems/buddy-strings) | |

Diff for: src/BackspaceStringCompare.java

@@ -0,0 +1,23 @@
+public class BackspaceStringCompare {
+    public boolean backspaceCompare(String s, String t) {
+        int i = nextCharIndex(s, s.length()), j = nextCharIndex(t, t.length());
+        while (i >= 0 && j >= 0) {
+            if (s.charAt(i) != t.charAt(j)) return false;
+            i = nextCharIndex(s, i);
+            j = nextCharIndex(t, j);
+        }
+        return i == -1 && j == -1;
+    }
+
+    private int nextCharIndex(String string, int currentIndex) {
+        for (int buffer = 0 ; buffer >= 0 ; currentIndex--) {
+            if (currentIndex == 0) {
+                currentIndex = -1;
+                break;
+            }
+            if (string.charAt(currentIndex - 1) == '#') buffer++;
+            else buffer--;
+        }
+        return currentIndex;
+    }
+}