PicoMite BASIC
https://beastacademy.com/all-ten
Uses the EXECUTE feature of PicoMite/MMBASIC to build an equation in a string and then execute it
The outer loops calculate the 24 permutations of the 4 numbers
For each of the permutations, we check every combination of operators, +, -, *, /, and concatenation
For each combination, we check all configurations of parentheses
We avoid divide by zero errors by checking if a number is divided by a difference (subtraction) contained in parentheses. Because the four numbers are positive integers, we can only get zero through subtraction, and we can't get zero without parentheses
For concatenation we need to insert a * for numbers touching a parentheses
Doesn't currently try to suppress equations equivalent e.g. through the commutative property
CLS :Print "All Ten solver"
Print
Dim lst(4) As string
Dim op(5) As string
op(0)="+"
op(1)="-"
op(2)="*"
op(3)="/"
op(4)=""
n=5
For i=0 To 3
Print "Number",i+1;
Input lst(i)
Next i
Print "Number to solve for ";
Print "(empty for all)";
Input n
Print
c=0
'p=0
For i=0 To 3
For j=0 To 3
If j=i Then
Continue For
EndIf
For k=0 To 3
If k=i Or k=j Then
Continue For
EndIf
m=6-i-j-k
For o1=0 To 4
For o2=0 To 4
For o3=0 To 4
e$="r="+lst(i)+op(o1)+lst(j)+op(o2)
e$=e$+lst(k)+op(o3)+lst(m)
exe e$
e$="r=("+lst(i)+op(o1)+lst(j)+")"
If o2=4 Then
opp$="*"
Else
opp$=op(o2)
EndIf
e$=e$+opp$+lst(k)+opp$+lst(m)
exe e$
If o1=3 And o2=1 Then
If Val(lst(j))-Val(lst(k))=0 Then
GoTo z1
EndIf
EndIf
If o1=4 Then
opp$="*"
Else
opp$=op(o1)
EndIf
e$="r="+lst(i)+opp$+"("+lst(j)
If o3=4 Then
opp2$="*"
Else
opp2$=op(o3)
EndIf
e$=e$+opp$+lst(k)+")"+opp2$+lst(m)
exe e$
z1:
If o2=3 And o3=1 Then
If Val(lst(k))-Val(lst(m))=0 Then
GoTo z2
EndIf
EndIf
If o2=4 Then
opp$="*"
Else
opp$=op(o2)
EndIf
e$="r="+lst(i)+op(o1)+lst(j)+opp$
e$=e$+"("+lst(k)+op(o3)+lst(m)+")"
exe e$
z2:
e$="r=("+lst(i)+op(o1)+lst(j)+op(o2)
If o3=4 Then
opp$="*"
Else
opp$=op(o3)
EndIf
e$=e$+lst(k)+")"+opp$+lst(m)
exe e$
If o1=3 Then
z$="r="+lst(j)+op(o2)
z$=z$+lst(k)+op(o3)+lst(m)
Execute z$
If r=0 Then
GoTo z3
EndIf
EndIf
If o1=4 Then
opp$="*"
Else
opp$=op(o1)
EndIf
e$="r="+lst(i)+opp$+"("+lst(j)+op(o2)
e$=e$+lst(k)+op(o3)+lst(m)+")"
exe e$
' 1
z3:
e$="r=(("+lst(i)+op(o1)+lst(j)+")"
If o3=4 Then
opp$="*"
Else
opp$=op(o3)
EndIf
If o2=4 Then
opp2$="*"
Else
opp2$=op(o2)
EndIf
e$=e$+opp2$+lst(k)+")"+opp$+lst(m)
exe e$
' 2
If o1=3 And o2=1 Then
If Val(lst(j))-Val(lst(k))=0 Then
GoTo z4
EndIf
EndIf
If o1=4 Then
opp$="*"
Else
opp$=op(o1)
EndIf
e$="r=("+lst(i)+opp$+"("+lst(j)
If o3=4 Then
opp$="*"
Else
opp$=op(o3)
EndIf
e$=e$+op(o2)+lst(k)+"))"+opp$+lst(m)
exe e$
' 3
z4:
If o1=3 Then
z$="r=("+lst(j)
If o3=4 Then
opp$="*"
Else
opp$=op(o3)
EndIf
z$=z$+op(o2)+lst(k)+")"+opp$+lst(m)
Execute z$
If r=0 Then
GoTo z5
EndIf
EndIf
If o1=4 Then
opp$="*"
Else
opp$=op(o1)
EndIf
If o3=4 Then
opp2$="*"
Else
opp2$=op(o3)
EndIf
If o2=1 Then
If lst(j)=lst(k) Then
If o3=3 Then
GoTo z5
EndIf
EndIf
EndIf
e$="r="+lst(i)+opp$+"(("+lst(j)
e$=e$+op(o2)+lst(k)+")"+opp2$+lst(m)
e$=e$+")"
exe e$
' 4
z5:
If o2=3 And o3=1 Then
If Val(lst(k))-Val(lst(m))=0 Then
GoTo z6
EndIf
EndIf
If o1=3 Then
If o2=4 Then
opp$="*"
Else
opp$=op(o2)
EndIf
z$="r="+lst(j)+opp$
z$=z$+"("+lst(k)+op(o3)+lst(m)+")"
Execute z$
If r=0 Then
GoTo z6
EndIf
EndIf
If o1=4 Then
opp$="*"
Else
opp$=op(1)
EndIf
If o2=4 Then
opp2$="*"
Else
opp2$=op(o2)
EndIf
e$="r="+lst(i)+opp$+"("+lst(j)+opp2$
e$=e$+"("+lst(k)+op(o3)+lst(m)+"))"
exe e$
' 5
z6:
If o2=3 And o3=1 Then
If Val(lst(k))-Val(lst(m))=0 Then
GoTo z7
EndIf
EndIf
If o2=4 Then
opp$="*"
Else
opp$=op(o2)
EndIf
e$="r=("+lst(i)+op(o1)+lst(j)+")"+opp$
e$=e$+"("+lst(k)+op(o3)+lst(m)+")"
exe e$
z7:
'End
Next o3
Next o2
Next o1
Next k
Next j
Next i
Print Str$(c)+" solutions found"
'Print Str$(p)+" permutations tried"
Sub exe e$
p=p+1
Execute e$
If n=0 Then
If r>0 And r<11 And r=Int(r) Then
Print r;Mid$(e$,2)
'Print r
If c Mod 24=0 And c>0 Then
Input "Press Enter to continue...",q
EndIf
c=c+1
EndIf
Else
If r=n Then
Print r;Mid$(e$,2)
If c Mod 24=0 And c>0 Then
Input "Press Enter to continue...",q
EndIf
c=c+1
EndIf
EndIf
End Sub