Create 397-integer-replacement.js

Author: everthis

397-integer-replacement.js

@@ -0,0 +1,26 @@
+/**
+ * @param {number} n
+ * @return {number}
+ */
+const integerReplacement = function(n, memo = {}) {
+    if (n === 1) return 0;
+    if (memo[n]) return memo[n];
+    memo[n] = n % 2 === 0 ? integerReplacement(n/2, memo) + 1 : Math.min(integerReplacement(n+1, memo), integerReplacement(n-1, memo)) + 1;
+    return memo[n]; 
+};
+
+// another
+const integerReplacement = function(n) {
+    let c = 0;
+    while (n !== 1) {
+        if ((n & 1) === 0) {
+            n >>>= 1;
+        } else if (n === 3 || ((n >>> 1) & 1) === 0) {
+            --n;
+        } else {
+            ++n;
+        }
+        ++c;
+    }
+    return c;  
+};