Merge pull request matthewsamuel95#79 from AnkitGuleria/subset_sum

Subset Sum problem in cpp(DP iterative Solution)

Author: matthewsamuel95

DP/subset_sum problem/subset_sum.cpp

@@ -0,0 +1,65 @@
+#include<iostream>
+using namespace std;
+
+bool subset_sum(int a[],int n, int sum)
+{
+       bool result[n+1][sum+1];
+        /*result[i][j] stores yes,no corresponding to whether there is a subset of sum j in subarray a[0....i-1]*/
+        
+        int i,j;
+        
+        for(i=0;i<=n;i++)
+        result[i][0]=true;/*always true for sum=0*/
+
+        for(j=1;j<=sum;j++)
+        result[0][j]=false;/* case of no element corresponding to non zero sum*/
+
+        for(i=1;i<=n;i++)
+        {
+            for(j=1;j<=sum;j++)
+            {
+                if(result[i-1][j]==true)
+                result[i][j]=true;
+
+                else
+                {
+                    if(a[i-1]>j)
+                    result[i][j]=false;
+                    else
+                    result[i][j]=result[i-1][j-a[i-1]];
+
+                }
+            }}
+
+        return result[n][sum];
+}
+
+     
+
+    int main()
+    {
+        int i,n,sum;
+
+        cout<<"Enter the value of sum"<<endl;
+        cin>>sum;
+
+        cout<<"Enter the number of elements in the set"<<endl;
+        cin>>n;
+
+        int a[n];
+        cout<<"Enter the values"<<endl;
+        for(i=0;i<n;i++)
+            cin>>a[i];
+
+    
+        bool answer=subset_sum(a,n,sum);
+        
+        if(answer==true)
+        cout<<"subset with the given sum exists";
+        else
+        cout<<"no required subset present";
+
+        cout<<endl; 
+        return 0;
+
+    }