Initial data commit

Task/Matrix-multiplication/Java/matrix-multiplication.java

@@ -0,0 +1,19 @@
+public static double[][] mult(double a[][], double b[][]){//a[m][n], b[n][p]
+   if(a.length == 0) return new double[0][0];
+   if(a[0].length != b.length) return null; //invalid dims
+
+   int n = a[0].length;
+   int m = a.length;
+   int p = b[0].length;
+
+   double ans[][] = new double[m][p];
+
+   for(int i = 0;i < m;i++){
+      for(int j = 0;j < p;j++){
+         for(int k = 0;k < n;k++){
+            ans[i][j] += a[i][k] * b[k][j];
+         }
+      }
+   }
+   return ans;
+}