Create Sequential Digits.java

Aroskar17 · Jan 23, 2022 · 9fffdbb · 9fffdbb
1 parent c347886
commit 9fffdbb
Showing 1 changed file with 21 additions and 0 deletions.
diff --git a/Leetcode Challenge/January/Java/Sequential Digits.java b/Leetcode Challenge/January/Java/Sequential Digits.java
@@ -0,0 +1,21 @@
+public List<Integer> sequentialDigits(int low, int high) {
+        List<Integer> res = new ArrayList();
+        for (int i = 1; i <= 9; i++) {
+            helper(0, i, low, high, res);
+        }
+        Collections.sort(res);
+        return res;
+    }
+
+    void helper(int cur, int digit, int low, int high, List<Integer> res) {    
+        cur = cur * 10 + digit;
+        if (cur > high)
+            return;
+
+        if (cur >= low) {
+            res.add(cur);
+        }
+
+        if (digit + 1 <= 9)
+            helper(cur, digit + 1, low, high, res);
+    }