Merge pull request #325 from cunhazera/prim-java

Adding prim in java

Algorithms/Prim.java

@@ -0,0 +1,50 @@
+public class Prim {
+
+    private int vertices = 5;
+
+    int minimum_key(int k[], int mst[]) {
+        int minimum = Integer.MAX_VALUE, min = 0, i;
+        for (i = 0; i < vertices; i++) {
+            if (mst[i] == 0 && k[i] < minimum) {
+                minimum = k[i];
+                min = i;
+            }
+        }
+        return min;
+    }
+
+    void prim(int[][] g) {
+        int[] parent = new int[vertices];
+        int[] k = new int[vertices];
+        int[] mst = new int[vertices];
+        int i, count, u, v;
+        for (i = 0; i < vertices; i++) {
+            k[i] = Integer.MAX_VALUE;
+            mst[i] = 0;
+        }
+
+        k[0] = 0;
+        parent[0] = -1;
+
+        for (count = 0; count < vertices - 1; count++) {
+            u = minimum_key(k, mst);
+            mst[u] = 1;
+            for (v = 0; v < vertices; v++)
+                if (g[u][v] != 0 && mst[v] == 0 && g[u][v] < k[v]) {
+                    parent[v] = u;
+                    k[v] = g[u][v];
+                }
+        }
+
+        for (i = 1; i < vertices; i++)
+            System.out.println(String.format("%d  %d    %d \n", parent[i], i, g[i][parent[i]]));
+    }
+
+
+    public static void main(String[] args) {
+        Prim instance = new Prim();
+        int[][] g = {{3, 2, 1, 9, 0}, {5, 1, 2, 10, 4}, {0, 4, 1, 0, 9}, {8, 10, 0, 2, 10}, {1, 6, 8, 11, 0}};
+        instance.prim(g);
+    }
+
+}