Add 251_Flatten_2D_Vector.java

Author: Sean Prashad

Design/251_Flatten_2D_Vector.java

@@ -0,0 +1,27 @@
+class Vector2D {
+    private int[][] v;
+    private int outer, inner;
+
+    public Vector2D(int[][] v) {
+        this.v = v;
+        outer = 0;
+        inner = 0;
+    }
+
+    private void advancedToNext() {
+        while (outer < v.length && inner == v[outer].length) {
+            inner = 0;
+            ++outer;
+        }
+    }
+
+    public int next() {
+        advancedToNext();
+        return v[outer][inner++];
+    }
+
+    public boolean hasNext() {
+        advancedToNext();
+        return outer < v.length;
+    }
+}