691031a7f9
RESTORE n now correctly positions past the DATA token so the next READ gets actual values instead of the token byte. New tests: Roman numerals, Luhn validator, Towers of Hanoi, 100 Doors, Pascal's triangle, type declarations, Hailstone sequence, multiplication table. 50 tests now pass.
23 lines
1010 B
QBasic
23 lines
1010 B
QBasic
10 REM Towers of Hanoi - iterative with explicit stack - Rosetta Code
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20 NDISKS = 4
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30 DIM SN(50), SF(50), ST(50), SV(50)
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40 SP = 0
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50 REM Push initial call: move NDISKS from A to C via B
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60 SP = SP + 1 : SN(SP) = NDISKS : SF(SP) = 1 : ST(SP) = 3 : SV(SP) = 2
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70 MOVES = 0
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80 IF SP = 0 THEN 200
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90 N = SN(SP) : F = SF(SP) : T = ST(SP) : V = SV(SP) : SP = SP - 1
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100 IF N = 0 THEN 80
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110 REM Push move(N-1, via, to, from) - this goes on stack FIRST (executed LAST)
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120 SP = SP + 1 : SN(SP) = N-1 : SF(SP) = V : ST(SP) = T : SV(SP) = F
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130 REM Push the actual move of disk N from F to T (sentinel N=0 above it)
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140 SP = SP + 1 : SN(SP) = 0 : SF(SP) = F : ST(SP) = T : SV(SP) = 0
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150 MOVES = MOVES + 1
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160 REM Push move(N-1, from, via, to)
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170 SP = SP + 1 : SN(SP) = N-1 : SF(SP) = F : ST(SP) = V : SV(SP) = T
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180 GOTO 80
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200 REM Should be 2^NDISKS - 1 = 15 moves
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210 EXPECTED = 2^NDISKS - 1
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220 IF MOVES <> EXPECTED THEN PRINT "FAIL: expected"; EXPECTED; "got"; MOVES : END
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230 PRINT "Hanoi OK:"; MOVES; "moves"
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