solves number of different integers in string

Author: anishLearnsToCode

README.md

@@ -439,7 +439,7 @@
 | 1791 | [Find Center of Star Graph](https://leetcode.com/problems/find-center-of-star-graph)                                                                      |                                                              [![Java](assets/java.png)](src/FindCenterOfStarGraph.java)                                                              |                                                                                                                                   |
 | 1796 | [Second Largest Digit in a String](https://leetcode.com/problems/second-largest-digit-in-a-string)                                                        |                                                           [![Java](assets/java.png)](src/SecondLargestDigitInAString.java)                                                           |                                                                                                                                   |
 | 1800 | [Maximum Ascending Subarray Sum](https://leetcode.com/problems/maximum-ascending-subarray-sum)                                                            |                                                           [![Java](assets/java.png)](src/MaximumAscendingSubArraySum.java)                                                           |                                                                                                                                   |
-| 1805 | [Number of Different Integers in a String](https://leetcode.com/problems/number-of-different-integers-in-a-string)                                        |                                                                                                                                                                                      |                                                                                                                                   |
+| 1805 | [Number of Different Integers in a String](https://leetcode.com/problems/number-of-different-integers-in-a-string)                                        |                                                        [![Java](assets/java.png)](src/NumberOfDifferentIntegersInString.java)                                                        |                                                                                                                                   |
 | 1812 | [Determine Color of a Chessboard Square](https://leetcode.com/problems/determine-color-of-a-chessboard-square)                                            |                                                                                                                                                                                      |                                                                                                                                   |
 | 1816 | [Truncate Sentence](https://leetcode.com/problems/truncate-sentence)                                                                                      |                                                                                                                                                                                      |                                                                                                                                   |
 | 1822 | [Sign of the Product of an Array](https://leetcode.com/problems/sign-of-the-product-of-an-array)                                                          |                                                                                                                                                                                      |                                                                                                                                   |

src/NumberOfDifferentIntegersInString.java

@@ -0,0 +1,27 @@
+import java.util.HashSet;
+import java.util.Set;
+
+public class NumberOfDifferentIntegersInString {
+    public int numDifferentIntegers(String word) {
+        final Set<String> uniqueIntegers = integersInString(word);
+        return uniqueIntegers.size();
+    }
+
+    private Set<String> integersInString(String s) {
+        final Set<String> integers = new HashSet<>();
+        boolean inNumber = false;
+        StringBuilder current = new StringBuilder();
+        for (int index = 0 ; index < s.length() ; index++) {
+            if (Character.isDigit(s.charAt(index))) {
+                if (!inNumber) inNumber = true;
+                current.append(s.charAt(index) == '0' && current.length() == 0 ? "" : s.charAt(index));
+                if (index == s.length() - 1) integers.add(current.toString());
+            } else if (inNumber) {
+                inNumber = false;
+                integers.add(current.toString());
+                current = new StringBuilder();
+            }
+        }
+        return integers;
+    }
+}