Merge pull request #1827 from CodingTestStudy2/염혜정

[염혜정] Day15

Author: github-actions[bot]

leetcode3/염혜정/1539. Kth Missing Positive Number.java

@@ -0,0 +1,21 @@
+// O(n)...
+
+class Solution {
+    public int findKthPositive(int[] arr, int k) {
+        Set<Integer> set = new HashSet<>();
+        for (int a : arr) set.add(a);
+        
+        int i = 1;
+        int cnt = 0;
+        int result = 0;
+        while(true) {
+            if (!set.contains(i)) cnt++;
+            if (cnt == k) {
+                result = i;
+                break;
+            }
+            i++;
+        }
+        return result;
+    }
+}