2016 Update

Task/Ethiopian-multiplication/Java/ethiopian-multiplication-4.java

@@ -1 +1,12 @@
-def pairs: while( .[0] > 0; [ (.[0] | halve), (.[1] | double) ]);
+function ethMult(m, n) {
+  var o = !isNaN(m) ? 0 : ''; // same technique works with strings
+  if (n < 1) return o;
+  while (n > 1) {
+    if (n & 1) o += m;  // 3. integer odd/even? (bit-wise and 1)
+    n >>= 1;            // 1. integer halved (by right-shift)
+    m += m;             // 2. integer doubled (addition to self)
+  }
+  return o + m;
+}
+
+ethMult(17, 34)