Merge pull request #22 from ArchanaPrabhu/patch-1

Solve Candy Pairing problem

Author: Kvaibhav01

Algorithms/C++/Greedy Algorithms/Candy_pairing.cpp

@@ -0,0 +1,43 @@
+#include<iostream>
+using namespace std;
+int a[100005];
+int main()
+{
+	int n,k;
+	long long available_pairs=0;
+	cin>>n>>k;
+	for(int i=1;i<=n;i++)
+	{
+		
+		cin>>a[i];
+		available_pairs+=a[i]/2;
+		a[i]-=1;
+		
+	}
+	
+	if(available_pairs < k)
+	{
+		cout<<"-1\n";
+	}
+	else
+	{
+		long long total=n;
+		long long pairs =0;
+		for(int i=1;i<=n;i++)
+		{
+			if(a[i]>=2)
+			{
+				total+=a[i]/2*2;
+				pairs+=a[i]/2;
+				a[i]=a[i]%2;
+			}
+		}
+		if(pairs >=k)
+		{
+			cout<<k*2+n-1<<"\n";
+			return 0;
+		}
+		cout<<total+k-pairs<<"\n";
+	}
+	return 0;
+}