Added program to implement Strassens Multiplication

Author: srijanishere

Programs/StrassensMultiplication.java

@@ -0,0 +1,61 @@
+//Program to multiply two square matrices using Strassen's Multiplication
+import java.util.*;
+public class StrassensMultiplication
+{
+    public static void main(String[] args) 
+    {
+        int n,m;
+        Scanner sc = new Scanner(System.in);
+        System.out.println("Enter the number of rows and columns of the first matrix : ");
+        n = sc.nextInt();
+        System.out.println("Enter the number of rows and columns of the second matrix : ");
+        m = sc.nextInt();
+        int[][] a = new int[n][n];
+        int[][] b = new int[m][m];
+        int[][] c = new int[2][2];
+        int i, j, m1, m2, m3, m4, m5, m6, m7;
+
+        //Taking input from the user
+        System.out.println("Enter all the elemens of the first matrix : ");
+        for(i=0; i<n; i++)
+        {
+            for(j=0; j<n; j++)
+            {
+                a[i][j] = sc.nextInt();
+            }
+        }
+        System.out.println("Enter all the elemens of the second matrix : ");
+        for(i=0; i<m; i++)
+        {
+            for(j=0; j<m; j++)
+            {
+                b[i][j] = sc.nextInt();
+            }
+        }
+
+        //Strassen's multiplication
+        m1= (a[0][0] + a[1][1]) * (b[0][0] + b[1][1]);
+        m2= (a[1][0] + a[1][1]) * b[0][0];
+        m3= a[0][0] * (b[0][1] - b[1][1]);
+        m4= a[1][1] * (b[1][0] - b[0][0]);
+        m5= (a[0][0] + a[0][1]) * b[1][1];
+        m6= (a[1][0] - a[0][0]) * (b[0][0]+b[0][1]);
+        m7= (a[0][1] - a[1][1]) * (b[1][0]+b[1][1]);
+
+        c[0][0] = m1 + m4- m5 + m7;
+        c[0][1] = m3 + m5;
+        c[1][0] = m2 + m4;
+        c[1][1] = m1 - m2 + m3 + m6;
+
+        //Display the output matrix
+        System.out.println("Ouput Matrix : ");
+        for(i=0; i<n; i++)
+        {
+            for(j=0; j<m; j++)
+            {
+                System.out.print(c[i][j]+"\t");
+            }
+            System.out.println();
+        }
+    }
+}