Create RankTransform.java

Leetcode/RankTransform.java

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+/**
+
+1331. Rank Transform of an Array
+Solved
+Easy
+Topics
+Companies
+Hint
+Given an array of integers arr, replace each element with its rank.
+
+The rank represents how large the element is. The rank has the following rules:
+
+Rank is an integer starting from 1.
+The larger the element, the larger the rank. If two elements are equal, their rank must be the same.
+Rank should be as small as possible.
+
+  **/
+class Solution {
+    public int[] arrayRankTransform(int[] arr) {
+        int n = arr.length,i=0;
+        TreeMap<Integer,Integer> map = new TreeMap<>();
+        for(i=0;i<n;i++){
+            map.put(arr[i],1);
+        }
+        i=1;
+        for(Map.Entry<Integer,Integer> entry:map.entrySet()){
+            map.put(entry.getKey(),i);
+            i++;
+        }
+        for(i=0;i<n;i++){
+            arr[i] = map.get(arr[i]);
+        }
+        return arr;
+    }
+}