diff options
Diffstat (limited to 'test/SemaCXX/constexpr-turing.cpp')
| -rw-r--r-- | test/SemaCXX/constexpr-turing.cpp | 16 |
1 files changed, 8 insertions, 8 deletions
diff --git a/test/SemaCXX/constexpr-turing.cpp b/test/SemaCXX/constexpr-turing.cpp index 07c04eff30839..75aefbf2ab7aa 100644 --- a/test/SemaCXX/constexpr-turing.cpp +++ b/test/SemaCXX/constexpr-turing.cpp @@ -33,24 +33,24 @@ constexpr Tape move(const Tape &old, Dir dir) { return Tape(old, dir); } // Run turing machine 'tm' on tape 'tape' from state 'state'. Return number of // steps taken until halt. constexpr unsigned run(const State *tm, const Tape &tape, unsigned state) { - return state == halt ? 1 : + return state == halt ? 0 : run(tm, move(update(tape, tm[state][tape.val].tape), tm[state][tape.val].dir), tm[state][tape.val].next) + 1; } -// 3-state busy beaver. 14 steps. +// 3-state busy beaver. S(bb3) = 21. constexpr State bb3[] = { - { { true, R, 1 }, { true, L, 2 } }, - { { true, L, 0 }, { true, R, 1 } }, - { { true, L, 1 }, { true, R, halt } } + { { true, R, 1 }, { true, R, halt } }, + { { true, L, 1 }, { false, R, 2 } }, + { { true, L, 2 }, { true, L, 0 } } }; -static_assert(run(bb3, Tape(), 0) == 14, ""); +static_assert(run(bb3, Tape(), 0) == 21, ""); -// 4-state busy beaver. 108 steps. +// 4-state busy beaver. S(bb4) = 107. constexpr State bb4[] = { { { true, R, 1 }, { true, L, 1 } }, { { true, L, 0 }, { false, L, 2 } }, { { true, R, halt }, { true, L, 3 } }, { { true, R, 3 }, { false, R, 0 } } }; -static_assert(run(bb4, Tape(), 0) == 108, ""); +static_assert(run(bb4, Tape(), 0) == 107, ""); |