solves #2283: Check if Number Has Equal Digit Count and Digit Value in java

Author: anishLearnsToCode

README.md

@@ -737,7 +737,7 @@
 | 2269 | [Find the K-Beauty of a Number](https://leetcode.com/problems/find-the-k-beauty-of-a-number)                                                                           |                                                                                   [![Java](assets/java.png)](src/FindTheKBeautyOfANumber.java)                                                                                   |                                                                                                                                   |
 | 2273 | [Find Resultant Array After Removing Anagrams](https://leetcode.com/problems/find-resultant-array-after-removing-anagrams)                                             |                                                                           [![Java](assets/java.png)](src/FindResultantArrayAfterRemovingAnagrams.java)                                                                           |                                                                                                                                   |
 | 2278 | [Percentage of Letter in String](https://leetcode.com/problems/percentage-of-letter-in-string)                                                                         |                                                                                 [![Java](assets/java.png)](src/PercentageOfLetterInString.java)                                                                                  |                                                                                                                                   |
-| 2283 | [Check if Number Has Equal Digit Count and Digit Value](https://leetcode.com/problems/check-if-number-has-equal-digit-count-and-digit-value)                           |                                                                                                                                                                                                                                  |                                                                                                                                   |
+| 2283 | [Check if Number Has Equal Digit Count and Digit Value](https://leetcode.com/problems/check-if-number-has-equal-digit-count-and-digit-value)                           |                                                                        [![Java](assets/java.png)](src/CheckIfNumberHasEqualDigitCountAndDigitValue.java)                                                                         |                                                                                                                                   |
 | 2287 | [Rearrange Characters to Make Target String](https://leetcode.com/problems/rearrange-characters-to-make-target-string)                                                 |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2293 | [Min Max Game](https://leetcode.com/problems/min-max-game)                                                                                                             |                                                                                                                                                                                                                                  |                                                                                                                                   |
 | 2299 | [Strong Password Checker II](https://leetcode.com/problems/strong-password-checker-ii)                                                                                 |                                                                                                                                                                                                                                  |                                                                                                                                   |

src/CheckIfNumberHasEqualDigitCountAndDigitValue.java

@@ -0,0 +1,27 @@
+// https://leetcode.com/problems/check-if-number-has-equal-digit-count-and-digit-value
+// T: O(|num|)
+// S: O(1)
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class CheckIfNumberHasEqualDigitCountAndDigitValue {
+    public boolean digitCount(String num) {
+        final Map<Integer, Integer> digitFrequencies = getDigitFrequencies(num);
+        for (int index = 0 ; index < num.length() ; index++) {
+            if ((num.charAt(index) - '0') != digitFrequencies.getOrDefault(index, 0)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    private Map<Integer, Integer> getDigitFrequencies(String number) {
+        final Map<Integer, Integer> frequencies = new HashMap<>();
+        for (int i = 0 ; i < number.length() ; i++) {
+            final int digit = number.charAt(i) - '0';
+            frequencies.put(digit, frequencies.getOrDefault(digit, 0) + 1);
+        }
+        return frequencies;
+    }
+}