Dice game probabilities: Difference between revisions

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=={{header|Ada}}==

<lang Ada>with Ada.Text_IO; use Ada.Text_IO;

with Ada.Numerics.Discrete_Random;

procedure Main is

package real_io is new Float_IO (Long_Float);

use real_io;

type Dice is record

Faces : Positive;

Num_Dice : Positive;

end record;

procedure Roll_Dice (The_Dice : in Dice; Count : out Natural) is

subtype Faces is Integer range 1 .. The_Dice.Faces;

package Die_Random is new Ada.Numerics.Discrete_Random (Faces);

use Die_Random;

Seed : Generator;

begin

Reset (Seed);

Count := 0;

for I in 1 .. The_Dice.Num_Dice loop

Count := Count + Random (Seed);

end loop;

end Roll_Dice;

function Win_Prob

(Dice_1 : Dice; Dice_2 : Dice; Tries : Positive) return Long_Float

is

Count_1 : Natural := 0;

Count_2 : Natural := 0;

Count_1_Wins : Natural := 0;

begin

for I in 1 .. Tries loop

Roll_Dice (Dice_1, Count_1);

Roll_Dice (Dice_2, Count_2);

if Count_1 > Count_2 then

Count_1_Wins := Count_1_Wins + 1;

end if;

end loop;

return Long_Float (Count_1_Wins) / Long_Float (Tries);

end Win_Prob;

D1 : Dice := (Faces => 4, Num_Dice => 9);

D2 : Dice := (Faces => 6, Num_Dice => 6);

D3 : Dice := (Faces => 10, Num_Dice => 5);

D4 : Dice := (Faces => 7, Num_Dice => 6);

P1 : Long_Float := Win_Prob (D1, D2, 1_000_000);

P2 : Long_Float := Win_Prob (D3, D4, 1_000_000);

begin

Put ("Dice D1 wins = ");

Put (Item => P1, Fore => 1, Aft => 7, Exp => 0);

New_Line;

Put ("Dice D2 wins = ");

Put (Item => P2, Fore => 1, Aft => 7, Exp => 0);

New_Line;

end Main;

</lang>

{{output}}

<pre>

Dice D1 wins = 0.5727800

Dice D2 wins = 0.6427660