diff options
Diffstat (limited to '2019')
| -rw-r--r-- | 2019/day07.c | 63 |
1 files changed, 53 insertions, 10 deletions
diff --git a/2019/day07.c b/2019/day07.c index d921683..c27aacd 100644 --- a/2019/day07.c +++ b/2019/day07.c @@ -2,11 +2,17 @@ #include <stdlib.h> #include <string.h> +enum { + Halt, + Input, + Output, +}; + struct Intcode { int ip; int mode[3]; int mem[1024]; - int in[2]; + int in; int out; }; @@ -14,20 +20,21 @@ static int *p(struct Intcode *m, int i) { return (m->mode[i - 1] ? &m->mem[m->ip + i] : &m->mem[m->mem[m->ip + i]]); } -static void run(struct Intcode *m) { - while (m->mem[m->ip] != 99) { +static int run(struct Intcode *m) { + for (;;) { m->mode[0] = m->mem[m->ip] / 100 % 10; m->mode[1] = m->mem[m->ip] / 1000 % 10; m->mode[2] = m->mem[m->ip] / 10000 % 10; switch (m->mem[m->ip] % 100) { break; case 1: *p(m, 3) = *p(m, 1) + *p(m, 2); m->ip += 4; break; case 2: *p(m, 3) = *p(m, 1) * *p(m, 2); m->ip += 4; - break; case 3: *p(m, 1) = m->in[0]; m->in[0] = m->in[1]; m->ip += 2; - break; case 4: m->out = *p(m, 1); m->ip += 2; + break; case 3: *p(m, 1) = m->in; m->ip += 2; return Input; + break; case 4: m->out = *p(m, 1); m->ip += 2; return Output; break; case 5: m->ip = (*p(m, 1) ? *p(m, 2) : m->ip + 3); break; case 6: m->ip = (*p(m, 1) ? m->ip + 3 : *p(m, 2)); break; case 7: *p(m, 3) = (*p(m, 1) < *p(m, 2)); m->ip += 4; break; case 8: *p(m, 3) = (*p(m, 1) == *p(m, 2)); m->ip += 4; + break; case 99: return Halt; break; default: abort(); } } @@ -42,23 +49,59 @@ int main(void) { for (int p = 0; p <= 044444; ++p) { int x = p; for (int i = 0; i < 5; ++i) { - amp[i].in[0] = x & 7; + amp[i].in = x & 7; x >>= 3; } for (int i = 0; i < 5; ++i) { - if (amp[i].in[0] > 4) goto skip; + if (amp[i].in > 4) goto skip; for (int j = 0; j < 5; ++j) { - if (i != j && amp[i].in[0] == amp[j].in[0]) goto skip; + if (i != j && amp[i].in == amp[j].in) goto skip; } } for (int i = 0; i < 5; ++i) { amp[i].ip = 0; memcpy(amp[i].mem, mem, sizeof(amp[i].mem)); - amp[i].in[1] = (i ? amp[i - 1].out : 0); - run(&[i]); + while (run(&[i]) != Input); + amp[i].in = (i ? amp[i - 1].out : 0); + while (run(&[i]) != Halt); } if (amp[4].out > max) max = amp[4].out; skip:; } printf("%d\n", max); + + max = 0; + for (int p = 0; p <= 044444; ++p) { + int x = p; + for (int i = 0; i < 5; ++i) { + amp[i].in = 5 + (x & 7); + amp[i].out = 0; + x >>= 3; + } + for (int i = 0; i < 5; ++i) { + if (amp[i].in > 9) goto skip2; + for (int j = 0; j < 5; ++j) { + if (i != j && amp[i].in == amp[j].in) goto skip2; + } + } + for (int i = 0; i < 5; ++i) { + amp[i].ip = 0; + memcpy(amp[i].mem, mem, sizeof(amp[i].mem)); + run(&[i]); + } + amp[0].in = 0; + for (int i = 0;;) { + int x = run(&[i]); + if (x == Output) { + int out = amp[i].out; + i = (i + 1) % 5; + amp[i].in = out; + } else if (x == Halt) { + break; + } + } + if (amp[4].out > max) max = amp[4].out; +skip2:; + } + printf("%d\n", max); } |