Thomas algorithm in java (#285)

* Add thomas algorithm in java

* Update thomas_algorithm.md

* Remove redundant blank line

Author: sklan

contents/thomas_algorithm/code/java/thomas.java

@@ -0,0 +1,37 @@
+public class thomas {
+    private static void thomasAlgorithm(double a[], double b[], double c[], double x[], int size) {
+
+        double y[] = new double[size];
+
+        y[0] = c[0] / b[0];
+        x[0] = x[0] / b[0];
+
+        for (int i = 1; i < size; ++i) {
+            double scale = 1.0 / (b[i] - a[i] * y[i - 1]);
+            y[i] = c[i] * scale;
+            x[i] = (x[i] - a[i] * x[i - 1]) * scale;
+        }
+
+        for (int i = size - 2; i >= 0; --i) {
+            x[i] -= y[i] * x[i + 1];
+        }
+    }
+
+    public static void main(String[] args) {
+        double a[] = {0.0, 2.0, 3.0};
+        double b[] = {1.0, 3.0, 6.0};
+        double c[] = {4.0, 5.0, 0.0};
+        double x[] = {7.0, 5.0, 3.0};
+
+        System.out.println("The system,\n");
+        System.out.println("[1.0  4.0  0.0][x] = [7.0]\n");
+        System.out.println("[2.0  3.0  5.0][y] = [5.0]\n");
+        System.out.println("[0.0  3.0  6.0][z] = [3.0]\n");
+        System.out.println("has the solution:\n");
+
+        thomasAlgorithm(a, b, c, x, 3);
+
+        for (int i = 0; i < 3; ++i)
+            System.out.println("[" + x[i] + "]\n");
+    }
+}

contents/thomas_algorithm/thomas_algorithm.md

@@ -102,6 +102,8 @@ The transformations are quite easy too, isn't that neat?
 [import, lang:"c_cpp"](code/c/thomas.c)
 {% sample lang="py" %}
 [import, lang:"python"](code/python/thomas.py)
+{% sample lang="java" %}
+[import, lang:"java"](code/java/thomas.java)
 {% sample lang="hs" %}
 [import, lang:"haskell"](code/haskell/thomas.hs)
 {% endmethod %}