langs a-z

Task/Binary-search/BASIC/binary-search-2.basic

@@ -0,0 +1,17 @@
+FUNCTION binary_search ( array() AS Integer, value AS Integer, lo AS Integer, hi AS Integer) AS Integer
+  DIM middle AS Integer
+
+  WHILE lo <= hi
+    middle = (hi + lo) / 2
+    SELECT CASE value
+      CASE IS < array(middle)
+	hi = middle - 1
+      CASE IS > array(middle)
+	lo = middle + 1
+      CASE ELSE
+	binary_search = middle
+	EXIT FUNCTION
+    END SELECT
+  WEND
+  binary_search = 0
+END FUNCTION