test: add tests for NumberOfSubsetEqualToGivenSum (#1661)

Dynamic-Programming/NumberOfSubsetEqualToGivenSum.js

@@ -1,5 +1,5 @@
 /*
-Given an array of non-negative integers and a value sum,
+Given an array of positive integers and a value sum,
 determine the total number of the subset with sum
 equal to the given sum.
 */
@@ -7,6 +7,13 @@ equal to the given sum.
   Given solution is O(n*sum) Time complexity and O(sum) Space complexity
 */
 function NumberOfSubsetSum(array, sum) {
+  if (sum < 0) {
+    throw new Error('The sum must be non-negative.')
+  }
+
+  if (!array.every((num) => num > 0)) {
+    throw new Error('All of the inputs of the array must be positive.')
+  }
   const dp = [] // create an dp array where dp[i] denote number of subset with sum equal to i
   for (let i = 1; i <= sum; i++) {
     dp[i] = 0
@@ -23,10 +30,4 @@ function NumberOfSubsetSum(array, sum) {
   return dp[sum]
 }
 
-// example
-
-// const array = [1, 1, 2, 2, 3, 1, 1]
-// const sum = 4
-// const result = NumberOfSubsetSum(array, sum)
-
 export { NumberOfSubsetSum }

Dynamic-Programming/tests/NumberOfSubsetEqualToGivenSum.test.js

@@ -0,0 +1,25 @@
+import { NumberOfSubsetSum } from '../NumberOfSubsetEqualToGivenSum'
+
+describe('Testing NumberOfSubsetSum', () => {
+  it.each([
+    [[], 0, 1],
+    [[], 1, 0],
+    [[1], 2, 0],
+    [[1, 2, 3, 4, 5], 0, 1],
+    [[1, 1, 1, 1, 1], 5, 1],
+    [[1, 1, 1, 1, 1], 4, 5],
+    [[1, 2, 3, 3], 6, 3],
+    [[10, 20, 30, 1], 31, 2],
+    [[1, 1, 2, 2, 3, 1, 1], 4, 18]
+  ])('check with %j and %i', (arr, sum, expected) => {
+    expect(NumberOfSubsetSum(arr, sum)).toBe(expected)
+  })
+
+  it.each([
+    [[1, 2], -1],
+    [[0, 2], 2],
+    [[1, -1], 0]
+  ])('throws for %j and %i', (arr, sum) => {
+    expect(() => NumberOfSubsetSum(arr, sum)).toThrowError()
+  })
+})