Create BinaryGap.js

LeetcodeProblems/BinaryGap.js

@@ -0,0 +1,69 @@
+/*
+https://leetcode.com/problems/binary-gap/description/
+
+Given a positive integer N, find and return the longest distance between two consecutive 1's in the binary representation of N.
+
+If there aren't two consecutive 1's, return 0. 
+
+Example 1:
+
+Input: 22
+Output: 2
+Explanation: 
+22 in binary is 0b10110.
+In the binary representation of 22, there are three ones, and two consecutive pairs of 1's.
+The first consecutive pair of 1's have distance 2.
+The second consecutive pair of 1's have distance 1.
+The answer is the largest of these two distances, which is 2.
+Example 2:
+
+Input: 5
+Output: 2
+Explanation: 
+5 in binary is 0b101.
+Example 3:
+
+Input: 6
+Output: 1
+Explanation: 
+6 in binary is 0b110.
+Example 4:
+
+Input: 8
+Output: 0
+Explanation: 
+8 in binary is 0b1000.
+There aren't any consecutive pairs of 1's in the binary representation of 8, so we return 0.
+*/
+
+/**
+ * @param {number} N
+ * @return {number}
+ */
+var binaryGap = function(N) {
+  var maxDist = 0;
+  var currentDist = 0;
+  while(N > 0) {
+    const bit = N % 2;
+    N >>= 1;
+    if(bit === 1) {
+      currentDist = 1;
+      while(N > 0 && N % 2 === 0 ) {
+        currentDist++;
+        N >>= 1; 
+      }
+      if(N !== 0 && currentDist > maxDist) { 
+        maxDist = currentDist;
+      }    
+    }
+  }
+  return maxDist;
+};
+
+var main = function() {
+  console.log(binaryGap(22)); // 10110
+  console.log(binaryGap(8)); // 1000
+}
+main();
+
+module.exports.main = main;