Merge pull request #7 from pro-js/basicMath

Search - 1

Author: zubayerhimel

lib/search.js

@@ -0,0 +1,32 @@
+/***
+ * binary-Search
+ * let array = [2,4,6,10,90,80]
+ * console.log(binarySearch(array, 6)); // 2
+ * console.log(binarySearch(array, 80)); // 4
+ * console.log(binarySearch(array, 70)); // -1
+ */
+export function binarySearch (array, target) {
+  array = array.sort(function(a, b){return a - b});
+  let startIndex = 0, endIndex = array.length - 1;
+  while(startIndex <= endIndex) {
+    let middleIndex = Math.floor((startIndex + endIndex) / 2);
+    if(target === array[middleIndex]) return middleIndex;
+    else if(target > array[middleIndex]) startIndex = middleIndex + 1;
+    else endIndex = middleIndex - 1;
+  }
+  return -1;
+}
+
+/***
+ * linear-Search
+ * let array = [2,4,6,10,90,80]
+ * console.log(linearSearch(array, 6)); // 2
+ * console.log(linearSearch(array, 80)); // 5
+ * console.log(linearSearch(array, 70)); // -1
+ */
+export function linearSearch (array, target) {
+  for (let i = 0; i < array.length; i++) {
+    if (target == array[i]) return i;
+  }
+  return -1;
+}