Add Lua code for chapter 1

zhangjiongwx · egonSchiele · commit dff0f3344714 · 2017-08-27T14:25:58.000-04:00
diff --git a/01_introduction_to_algorithms/lua/01_binary_search.lua b/01_introduction_to_algorithms/lua/01_binary_search.lua
@@ -0,0 +1,24 @@
+function binary_search(table, value)
+    -- Lua arrays start with 1
+    local low, high = 1, #table
+    
+    while low <= high do
+        local mid = math.floor((low + high) / 2)
+        local guess = table[mid]
+        
+        if guess == value then
+            return mid
+        elseif guess > value then
+            high = mid - 1
+        else
+            low = mid + 1
+        end
+    end
+    
+    return nil
+end
+
+local my_table = {1, 3, 5, 7, 9}
+
+print(binary_search(my_table, 3)) -- => 2
+print(binary_search(my_table, -1)) -- => nil
