Done with finding pair sum.

Author: simdi

list/pair-number-sum/index.js

@@ -0,0 +1,25 @@
+/*
+* @author: Chisimdi Damian Ezeanieto
+* @date: 22/01/2020
+*/
+
+const pairNumberSum = (arr, k) => {
+  const result = [];
+  // Naive solution
+  // Use two loops to loop through the array.
+  let i = 0;
+  while(i < arr.length) {
+    let deficit = k - arr[i];
+    let newArray = arr.slice(i);
+    let findIndex = newArray.indexOf(deficit);
+    if (findIndex > -1) {
+      let findItem = newArray[findIndex];
+      let pairs = [arr[i], findItem];
+      result.push(pairs);
+    }
+    i++;
+  }
+  return result;
+}
+
+module.exports = pairNumberSum;

list/pair-number-sum/test.js

@@ -0,0 +1,11 @@
+/*
+* @author: Chisimdi Damian Ezeanieto
+* @date: 22/01/2020
+*/
+const pairNumberSum = require('./index');
+test('pairNumberSum is a function', () => {
+    expect(typeof pairNumberSum).toEqual('function');
+});
+test('pairNumberSum [8,2,54,65,23,7,45] to give [2,7,8,23,45,54,65]', () => {
+    expect(pairNumberSum([1, 9, 11, 13, 2, 3, 7, 5], 12)).toEqual([[1, 11], [9,3], [7, 5]]);
+});

package.json

@@ -4,7 +4,7 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "jest --watch"
   },
   "repository": {
     "type": "git",