add 1742

Author: fishercoder1534

README.md

@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ ★
 
 |  #  |      Title     |   Solutions   | Video  | Difficulty  | Tag                   
 |-----|----------------|---------------|--------|-------------|-------------
+|1742|[Maximum Number of Balls in a Box](https://leetcode.com/problems/maximum-number-of-balls-in-a-box/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1742.java) ||Easy|Array|
 |1736|[Latest Time by Replacing Hidden Digits](https://leetcode.com/problems/latest-time-by-replacing-hidden-digits/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1736.java) ||Easy|String, Greedy|
 |1733|[Minimum Number of People to Teach](https://leetcode.com/problems/minimum-number-of-people-to-teach/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1733.java) ||Medium|Array, Greedy|
 |1732|[Find the Highest Altitude](https://leetcode.com/problems/find-the-highest-altitude/)|[Solution](../master/src/main/java/com/fishercoder/solutions/_1732.java) ||Easy|Array|

src/main/java/com/fishercoder/solutions/_1742.java

@@ -0,0 +1,26 @@
+package com.fishercoder.solutions;
+
+import java.util.HashMap;
+import java.util.Map;
+
+public class _1742 {
+    public static class Solution1 {
+        public int countBalls(int lowLimit, int highLimit) {
+            Map<Integer, Integer> map = new HashMap<>();
+            for (int limit = lowLimit, i = 0; limit <= highLimit; limit++, i++) {
+                int number = 0;
+                int tmp = limit;
+                do {
+                    number += tmp % 10;
+                    tmp /= 10;
+                } while (tmp != 0);
+                map.put(number, map.getOrDefault(number, 0) + 1);
+            }
+            int maxBalls = 0;
+            for (int c : map.keySet()) {
+                maxBalls = Math.max(maxBalls, map.get(c));
+            }
+            return maxBalls;
+        }
+    }
+}