From 735f173fc2275e7ff8814705ab65dbce40f748ea Mon Sep 17 00:00:00 2001
From: rverma13927 <65550578+rverma13927@users.noreply.github.com>
Date: Fri, 22 May 2020 08:44:22 +0530
Subject: [PATCH] Number of Subset equal to given sum (#174)

* Number of Subset equal to given sum

* Update and rename Number of Subset equal to given sum to NumberOfSubsetEqualToGivenSum.js

* Update NumberOfSubsetEqualToGivenSum.js
---
 .../NumberOfSubsetEqualToGivenSum.js          | 32 +++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 Dynamic-Programming/NumberOfSubsetEqualToGivenSum.js

diff --git a/Dynamic-Programming/NumberOfSubsetEqualToGivenSum.js b/Dynamic-Programming/NumberOfSubsetEqualToGivenSum.js
new file mode 100644
index 000000000..f45d06985
--- /dev/null
+++ b/Dynamic-Programming/NumberOfSubsetEqualToGivenSum.js
@@ -0,0 +1,32 @@
+/*
+Given an array of non-negative integers and a value sum,
+determine the total number of the subset with sum
+equal to the given sum.
+*/
+/*
+ Given solution is O(n*sum) Time complexity and O(sum) Space complexity
+*/
+function NumberOfSubsetSum (array, sum) {
+  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
+  }
+  dp[0] = 1 // since sum equal to 0 is always possible with no element in subset
+
+  for (let i = 0; i < array.length; i++) {
+    for (let j = sum; j >= array[i]; j--) {
+      if (j - array[i] >= 0) {
+        dp[j] += dp[j - array[i]]
+      }
+    }
+  }
+  return dp[sum]
+}
+
+function main () {
+  const array = [1, 1, 2, 2, 3, 1, 1]
+  const sum = 4
+  const result = NumberOfSubsetSum(array, sum)
+  console.log(result)
+}
+main()