Dynamic Programming - Subset Sum Problem

DynamicProgramming/Subset_sum.js

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+/* 
+Problem Statement - 
+Given a set of non-negative integers, and a value sum, determine if there is a subset of the given set with sum equal to given sum. 
+
+Input: set[] = {3, 34, 4, 12, 5, 2}, sum = 9
+Output: True  
+
+*/
+
+// Returns true if there is a subset of set[] with sum equal to given sum
+function isSubsetSum(set, n, sum)
+{
+    // Value of subset[i][j] will be true if there is a subset of set[0..j-1] with sum equal to i
+    let subset = new Array(sum + 1);
+
+    for(let i = 0; i < sum + 1; i++)
+    {
+        subset[i] = new Array(sum + 1);
+        for(let j = 0; j < n + 1; j++)
+        {
+            subset[i][j] = 0;
+        }
+    }
+
+    // If sum is 0, then answer is true
+    for (let i = 0; i <= n; i++)
+        subset[0][i] = true;
+
+    // If sum is not 0 and set is empty, then answer is false
+    for (let i = 1; i <= sum; i++)
+        subset[i][0] = false;
+
+    // Fill the subset table in bottom up manner
+    for (let i = 1; i <= sum; i++) {
+        for (let j = 1; j <= n; j++) {
+            subset[i][j] = subset[i][j - 1];
+            if (i >= set[j - 1])
+                subset[i][j] = subset[i][j]
+                            || subset[i - set[j - 1]][j - 1];
+        }
+    }
+
+    return subset[sum][n];
+}
+
+let set = [ 3, 34, 4, 12, 5, 2 ];
+let sum = 9;
+let n = set.length;
+if (isSubsetSum(set, n, sum) == true)
+document.write("Found a subset" + " with given sum");
+else
+document.write("No subset with" + " given sum");