pure math solution to https://codingwithmanny.medium.com/how-to-solve…

…-binary-gap-cda3c3e980b8

package.json

@@ -0,0 +1,14 @@
+{
+  "name": "javascript-challenges",
+  "version": "1.0.0",
+  "type": "module",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {}
+}

sequence.js

@@ -0,0 +1,48 @@
+// find longest sequence of 0 between to 1s in the binary version representation
+// e.g. n=5 -> n=101 , has sequence of '0' which is of length 1
+import assert from "assert";
+
+function sequence101(n) {
+    let maxSequenceLength = 0;
+    let currentSequenceLength = 0
+    let foundFirst1 = false;
+
+    while (n > 0) {
+        if (n % 2 === 1 && !foundFirst1) {
+            foundFirst1 = true;
+        } else if (n % 2 === 0 && !foundFirst1) {
+            // do nothing
+        } else if (n % 2 === 0 && foundFirst1) {
+            currentSequenceLength += 1;
+        } else if (n % 2 === 1 && foundFirst1) {
+            maxSequenceLength = Math.max(currentSequenceLength, maxSequenceLength);
+            currentSequenceLength = 0;
+        }
+
+        n >>= 1;
+    }
+    return maxSequenceLength;
+}
+
+
+function testSequence101() {
+    assert(sequence101(0) === 0);  // 0
+    assert(sequence101(1) === 0);  // 1
+    assert(sequence101(2) === 0);  // 10
+    assert(sequence101(3) === 0);  // 11
+    assert(sequence101(4) === 0);  // 100
+    assert(sequence101(5) === 1);  // 101
+    assert(sequence101(9) === 2);  // 1001
+    assert(sequence101(10) === 1); // 1010
+    assert(sequence101(11) === 1); // 1011
+    assert(sequence101(12) === 0); // 1110
+    assert(sequence101(41) === 2); // 101001
+    assert(sequence101(277) === 3);  // 100010101
+    assert(sequence101(1000) === 1); // 1111101000
+    assert(sequence101(1160) === 3); // 10010001000
+    assert(sequence101(1161) === 3); // 10010001001
+    assert(sequence101(-1) === 0);
+    console.log("success")
+}
+
+testSequence101()