Merge pull request #811 from aconconi/33-lua-port

33_Dice Lua port.

33_Dice/lua/dice.lua

@@ -0,0 +1,113 @@
+--[[
+Dice
+
+From: BASIC Computer Games (1978)
+Edited by David H. Ahl
+
+    "Not exactly a game, this program simulates rolling
+    a pair of dice a large number of times and prints out
+    the frequency distribution.  You simply input the
+    number of rolls.  It is interesting to see how many
+    rolls are necessary to approach the theoretical
+    distribution:
+
+    2  1/36  2.7777...%
+    3  2/36  5.5555...%
+    4  3/36  8.3333...%
+    etc.
+
+    "Daniel Freidus wrote this program while in the
+     seventh grade at Harrison Jr-Sr High School,
+    Harrison, New York."
+
+
+Lua port by Alex Conconi, 2022.
+]]--
+
+
+local function print_intro()
+    print("\n                   Dice")
+    print("Creative Computing  Morristown, New Jersey")
+    print("\n\n")
+    print("This program simulates the rolling of a")
+    print("pair of dice.")
+    print("You enter the number of times you want the computer to")
+    print("'roll' the dice.   Watch out, very large numbers take")
+    print("a long time.  In particular, numbers over 5000.")
+end
+
+
+local function ask_how_many_rolls()
+    while true do
+        -- Print prompt and read a valid number from stdin
+        print("\nHow many rolls?")
+        local num_rolls = tonumber(io.stdin:read("*l"))
+        if num_rolls then
+            return num_rolls
+        else
+            print("Please enter a valid number.")
+        end
+    end
+end
+
+
+local function ask_try_again()
+    while true do
+        -- Print prompt and read a yes/no answer from stdin,
+        -- accepting only 'yes', 'y', 'no' or 'n' (case insensitive)
+        print("\nTry again? ([y]es / [n]o)")
+        local answer = string.lower(io.stdin:read("*l"))
+        if answer == "yes" or  answer == "y" then
+            return true
+        elseif answer == "no" or answer == "n" then
+            return false
+        else
+            print("Please answer '[y]es' or '[n]o'.")
+        end
+    end
+end
+
+
+local function roll_dice(num_rolls)
+    -- Initialize a table to track counts of roll outcomes
+    local counts = {}
+    for i=2, 12 do
+        counts[i] = 0
+    end
+
+    -- Roll the dice num_rolls times and update outcomes counts accordingly
+    for _=1, num_rolls do
+        local roll_total = math.random(1, 6) + math.random(1, 6)
+        counts[roll_total] = counts[roll_total] + 1
+    end
+
+    return counts
+end
+
+
+function print_results(counts)
+    print("\nTotal Spots   Number of Times")
+    for roll_total, count in pairs(counts) do
+        print(string.format(" %-14d%d", roll_total, count))
+    end
+end
+
+
+local function dice_main()
+    print_intro()
+
+    -- initialize the random number generator
+    math.randomseed(os.time())
+
+    -- main game loop
+    local keep_playing = true
+    while keep_playing do
+        local num_rolls = ask_how_many_rolls()
+        local counts = roll_dice(num_rolls)
+        print_results(counts)
+        keep_playing = ask_try_again()
+    end
+end
+
+
+dice_main()