Source code in the focal programming language

01.10 T %5.02," RANDOM";S CU=0
01.20 F Z=1,2000;D 5;S CU=CU+SU
01.30 T CU/20,!,"OPTIMAL";S CU=0
01.40 F Z=1,2000;D 6;S CU=CU+SU
01.50 T CU/20,!
01.60 Q

02.01 C-- PUT CARDS IN RANDOM DRAWERS
02.10 F X=1,100;S D(X)=X
02.20 F X=1,99;D 2.3;S B=D(X);S D(X)=D(A);S D(A)=B
02.30 D 2.4;S A=X+FITR(A*(101-X))
02.40 S A=FABS(FRAN()*10);S A=A-FITR(A)

03.01 C-- PRISONER X TRIES UP TO 50 RANDOM DRAWERS
03.10 S TR=50;S SU=0
03.20 D 2.4;I (X-D(A))3.3,3.4,3.3
03.30 S TR=TR-1;I (TR),3.5,3.2
03.40 S SU=1;R
03.50 S SU=0

04.01 C-- PRISONER X TRIES OPTIMAL METHOD
04.10 S TR=50;S SU=0;S A=X
04.20 I (X-D(A))4.3,4.4,4.3
04.30 S TR=TR-1;S A=D(A);I (TR),4.5,4.2
04.40 S SU=1;R
04.50 S SU=0

05.01 C-- PRISONERS TRY RANDOM METHOD UNTIL ONE FAILS
05.10 D 2;S X=1
05.20 I (X-101)5.3,5.4
05.30 D 3;S X=X+1;I (SU),5.4,5.2
05.40 R

06.01 C-- PRISONERS TRY OPTIMAL METHOD UNTIL ONE FAILS
06.10 D 2;S X=1
06.20 I (X-101)6.3,6.4
06.30 D 4;S X=X+1;I (SU),6.4,6.2
06.40 R