Added Activity Selection problem of greedy algorithm using java language

Greedy Algorithms/Activity Selection/Java/Activity_Selection.java

@@ -0,0 +1,53 @@
+import java.util.*;
+class A
+{
+	public int find(int a[],int b[],int n)
+	{
+		int count=1;
+		for(int i=1;i<n;i++)
+		{
+			int key=b[i];
+			int key1=a[i];
+			int j=i-1;
+			while(j>=0&&b[j]>key)
+			{
+				b[j+1]=b[j];
+				a[j+1]=a[j];
+				j--;
+			}
+			b[j+1]=key;
+			a[j+1]=key1;
+		}
+		int i=0;
+		for(int j=1;j<n;j++)
+		{
+			if(b[i]<=a[j])
+			{
+				i=j;
+				count++;
+
+			}
+		}
+		return count;
+	}
+}
+class Activity_Selection
+{
+	public static void main(String args[])
+	{
+		Scanner sc=new Scanner(System.in);
+		System.out.println("Enter the no. of activities");
+		int n=sc.nextInt();
+		int start[]=new int[n];
+		int finish[]=new int[n];
+		System.out.println("Enter the start and finish time");
+		for(int i=0;i<n;i++)
+		{
+			start[i]=sc.nextInt();
+			finish[i]=sc.nextInt();
+		}
+		A ob=new A();
+		int ans=ob.find(start,finish,n);
+		System.out.println("Maximum activity can be done = "+ans);
+	}
+}