Create Smallest positive missing number

Smallest positive missing number

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+//Smallest positive missing number
+
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int t = Integer.parseInt(br.readLine().trim());
+
+        while(t-- > 0) {
+            String input = br.readLine().trim();
+            String[] tokens = input.split(" ");
+            int[] arr = new int[tokens.length];
+
+            for(int i = 0; i < tokens.length; i++) {
+                arr[i] = Integer.parseInt(tokens[i]);
+            }
+
+            Solution ob = new Solution();
+            int res = ob.missingNumber(arr);
+
+            System.out.println(res);
+        }
+    }
+}
+
+class Solution {
+    public int missingNumber(int[] arr) {
+        Map<Integer, Integer> map = new HashMap<>();
+
+        for(int i = 0; i < arr.length; i++) {
+            map.put(arr[i], 1);
+        }
+
+        int i = 1;
+        while(true) {
+            if(!map.containsKey(i)) {
+                break;
+            }
+
+            i++;
+        }
+
+        return i;
+    }
+}