Create 2094-finding-3-digit-even-numbers.js

Author: everthis

2094-finding-3-digit-even-numbers.js

@@ -0,0 +1,49 @@
+/**
+ * @param {number[]} digits
+ * @return {number[]}
+ */
+const findEvenNumbers = function(digits) {
+  const set = new Set(), visited = new Set()
+  helper(0, [])
+  const res = Array.from(set)
+  res.sort((a, b) => a - b)
+  return res
+  
+  function helper(idx, cur) {
+    if(cur.length === 3) {
+      set.add(+cur.join(''))
+      return
+    }
+    for(let i = 0; i < digits.length; i++) {
+      if(visited.has(i)) continue
+      const d = digits[i]
+      if(d === 0) {
+        if(cur.length === 0) continue
+        else {
+          cur.push(d)
+          visited.add(i)
+          helper(i + 1, cur)
+          visited.delete(i)
+          cur.pop()
+        }
+      } else {
+        const isEven = d % 2 === 0
+        if(cur.length === 3 - 1) {
+          if(isEven) {
+            cur.push(d)
+                      visited.add(i)
+            helper(i + 1, cur)
+                      visited.delete(i)
+            cur.pop()
+          } else continue
+        } else {
+           cur.push(d)
+                    visited.add(i)
+            helper(i + 1, cur)
+                    visited.delete(i)
+            cur.pop()
+        }
+      }
+    }
+  }
+};