2019 day 7, part 1

2019/day07/INPUT.txt

@@ -1 +1 @@
-3,225,1,225,6,6,1100,1,238,225,104,0,1101,86,8,225,1101,82,69,225,101,36,65,224,1001,224,-106,224,4,224,1002,223,8,223,1001,224,5,224,1,223,224,223,102,52,148,224,101,-1144,224,224,4,224,1002,223,8,223,101,1,224,224,1,224,223,223,1102,70,45,225,1002,143,48,224,1001,224,-1344,224,4,224,102,8,223,223,101,7,224,224,1,223,224,223,1101,69,75,225,1001,18,85,224,1001,224,-154,224,4,224,102,8,223,223,101,2,224,224,1,224,223,223,1101,15,59,225,1102,67,42,224,101,-2814,224,224,4,224,1002,223,8,223,101,3,224,224,1,223,224,223,1101,28,63,225,1101,45,22,225,1101,90,16,225,2,152,92,224,1001,224,-1200,224,4,224,102,8,223,223,101,7,224,224,1,223,224,223,1101,45,28,224,1001,224,-73,224,4,224,1002,223,8,223,101,7,224,224,1,224,223,223,1,14,118,224,101,-67,224,224,4,224,1002,223,8,223,1001,224,2,224,1,223,224,223,4,223,99,0,0,0,677,0,0,0,0,0,0,0,0,0,0,0,1105,0,99999,1105,227,247,1105,1,99999,1005,227,99999,1005,0,256,1105,1,99999,1106,227,99999,1106,0,265,1105,1,99999,1006,0,99999,1006,227,274,1105,1,99999,1105,1,280,1105,1,99999,1,225,225,225,1101,294,0,0,105,1,0,1105,1,99999,1106,0,300,1105,1,99999,1,225,225,225,1101,314,0,0,106,0,0,1105,1,99999,7,677,677,224,102,2,223,223,1005,224,329,1001,223,1,223,1008,226,226,224,1002,223,2,223,1005,224,344,1001,223,1,223,1107,677,226,224,1002,223,2,223,1006,224,359,1001,223,1,223,107,677,677,224,102,2,223,223,1005,224,374,101,1,223,223,1108,677,226,224,102,2,223,223,1005,224,389,1001,223,1,223,1007,677,677,224,1002,223,2,223,1005,224,404,101,1,223,223,1008,677,226,224,102,2,223,223,1005,224,419,101,1,223,223,1108,226,677,224,102,2,223,223,1006,224,434,1001,223,1,223,8,677,226,224,1002,223,2,223,1005,224,449,101,1,223,223,1008,677,677,224,1002,223,2,223,1006,224,464,1001,223,1,223,1108,226,226,224,1002,223,2,223,1005,224,479,1001,223,1,223,1007,226,677,224,102,2,223,223,1005,224,494,1001,223,1,223,1007,226,226,224,102,2,223,223,1005,224,509,101,1,223,223,107,677,226,224,1002,223,2,223,1006,224,524,1001,223,1,223,108,677,677,224,102,2,223,223,1006,224,539,101,1,223,223,7,677,226,224,102,2,223,223,1006,224,554,1001,223,1,223,1107,226,677,224,102,2,223,223,1005,224,569,101,1,223,223,108,677,226,224,1002,223,2,223,1006,224,584,101,1,223,223,108,226,226,224,102,2,223,223,1006,224,599,1001,223,1,223,1107,226,226,224,102,2,223,223,1006,224,614,1001,223,1,223,8,226,677,224,102,2,223,223,1006,224,629,1001,223,1,223,107,226,226,224,102,2,223,223,1005,224,644,101,1,223,223,8,226,226,224,102,2,223,223,1006,224,659,101,1,223,223,7,226,677,224,102,2,223,223,1005,224,674,101,1,223,223,4,223,99,226
+3,8,1001,8,10,8,105,1,0,0,21,30,39,64,81,102,183,264,345,426,99999,3,9,1001,9,2,9,4,9,99,3,9,1002,9,4,9,4,9,99,3,9,1002,9,5,9,101,2,9,9,102,3,9,9,1001,9,2,9,1002,9,2,9,4,9,99,3,9,1002,9,3,9,1001,9,5,9,1002,9,3,9,4,9,99,3,9,102,4,9,9,1001,9,3,9,102,4,9,9,1001,9,5,9,4,9,99,3,9,101,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,1,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,1,9,4,9,3,9,101,1,9,9,4,9,3,9,101,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,1,9,4,9,99,3,9,1002,9,2,9,4,9,3,9,101,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,101,1,9,9,4,9,3,9,101,1,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,1,9,4,9,3,9,1001,9,1,9,4,9,3,9,102,2,9,9,4,9,99,3,9,101,1,9,9,4,9,3,9,101,2,9,9,4,9,3,9,101,1,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,101,1,9,9,4,9,99,3,9,102,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,101,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,1,9,4,9,3,9,101,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,2,9,4,9,99,3,9,101,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,1001,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,101,1,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,1,9,4,9,3,9,1001,9,2,9,4,9,3,9,101,2,9,9,4,9,3,9,101,1,9,9,4,9,99

2019/day07/README.org

@@ -93,10 +93,73 @@ Here are some example programs:
 Try every combination of phase settings on the amplifiers. /What is the
 highest signal that can be sent to the thrusters?/
 
-To begin, [[file:7/input][get your puzzle input]].
+Your puzzle answer was =65464=.
 
-Answer:
+The first half of this puzzle is complete! It provides one gold star: *
 
-You can also [Shareon
+** --- Part Two ---
-[[https://twitter.com/intent/tweet?text=%22Amplification+Circuit%22+%2D+Day+7+%2D+Advent+of+Code+2019&url=https%3A%2F%2Fadventofcode%2Ecom%2F2019%2Fday%2F7&related=ericwastl&hashtags=AdventOfCode][Twitter]]
+It's no good - in this configuration, the amplifiers can't generate a
-[[javascript:void(0);][Mastodon]]] this puzzle.
+large enough output signal to produce the thrust you'll need. The Elves
+quickly talk you through rewiring the amplifiers into a /feedback loop/:
+
+#+BEGIN_EXAMPLE
+        O-------O  O-------O  O-------O  O-------O  O-------O
+  0 -+->| Amp A |->| Amp B |->| Amp C |->| Amp D |->| Amp E |-.
+     |  O-------O  O-------O  O-------O  O-------O  O-------O |
+     |                                                        |
+     '--------------------------------------------------------+
+                                                              |
+                                                              v
+                                                       (to thrusters)
+#+END_EXAMPLE
+
+Most of the amplifiers are connected as they were before; amplifier
+=A='s output is connected to amplifier =B='s input, and so on.
+/However,/ the output from amplifier =E= is now connected into amplifier
+=A='s input. This creates the feedback loop: the signal will be sent
+through the amplifiers /many times/.
+
+In feedback loop mode, the amplifiers need /totally different phase
+settings/: integers from =5= to =9=, again each used exactly once. These
+settings will cause the Amplifier Controller Software to repeatedly take
+input and produce output many times before halting. Provide each
+amplifier its phase setting at its first input instruction; all further
+input/output instructions are for signals.
+
+Don't restart the Amplifier Controller Software on any amplifier during
+this process. Each one should continue receiving and sending signals
+until it halts.
+
+All signals sent or received in this process will be between pairs of
+amplifiers except the very first signal and the very last signal. To
+start the process, a =0= signal is sent to amplifier =A='s input
+/exactly once/.
+
+Eventually, the software on the amplifiers will halt after they have
+processed the final loop. When this happens, the last output signal from
+amplifier =E= is sent to the thrusters. Your job is to /find the largest
+output signal that can be sent to the thrusters/ using the new phase
+settings and feedback loop arrangement.
+
+Here are some example programs:
+
+- Max thruster signal /=139629729=/ (from phase setting sequence
+  =9,8,7,6,5=):
+
+  #+BEGIN_EXAMPLE
+    3,26,1001,26,-4,26,3,27,1002,27,2,27,1,27,26,
+    27,4,27,1001,28,-1,28,1005,28,6,99,0,0,5
+  #+END_EXAMPLE
+
+- Max thruster signal /=18216=/ (from phase setting sequence
+  =9,7,8,5,6=):
+
+  #+BEGIN_EXAMPLE
+    3,52,1001,52,-5,52,3,53,1,52,56,54,1007,54,5,55,1005,55,26,1001,54,
+    -5,54,1105,1,12,1,53,54,53,1008,54,0,55,1001,55,1,55,2,53,55,53,4,
+    53,1001,56,-1,56,1005,56,6,99,0,0,0,0,10
+  #+END_EXAMPLE
+
+Try every combination of the new phase settings on the amplifier
+feedback loop. /What is the highest signal that can be sent to the
+thrusters?/

2019/day07/aoc-c.c

@@ -41,10 +41,13 @@ typedef struct {
     char     *mnemo;
 } ops_t;
 
+#define MAXINPUT 4
 #define MAXOPS   1024
 typedef struct {
     int length;                                   /* total program length */
     int cur;                                      /* current position */
+    int curinput, lastinput;
+    int input[MAXINPUT];                          /* input */
     int mem [MAXOPS];                             /* should really be dynamic */
 } program_t;
 
@@ -72,7 +75,45 @@ static int _flag_pow10[] = {1, 100, 1000, 10000};
         INDIRECT(p, n + i) = val; }   \
     while (0)
 
-static int run(program_t *p, int in)
+/**
+ * permute - get next permutation of an array of integers
+ * @len:   length of array
+ * @array: address of array
+ *
+ * Algorithm: lexicographic permutations
+ * https://en.wikipedia.org/wiki/Permutation#Generation_in_lexicographic_order
+ * Before the initial call, the array must be sorted (e.g. 0 2 3 5)
+ *
+ * Return: 1 if next permutation was found, 0 if no more permutation.
+ *
+ */
+static int permute_next(int len, int *array)
+{
+    int k, l;
+
+    /* 1. Find the largest index k such that a[k] < a[k + 1] */
+    for (k = len - 2; k >= 0 && array[k] >= array[k + 1]; k--)
+        ;
+    /*  No more permutations */
+    if (k < 0)
+        return 0;
+    /* 2. Find the largest index l greater than k such that a[k] < a[l] */
+    for (l = len - 1; array[l] <= array[k]; l--)
+        ;
+    /* 3. Swap the value of a[k] with that of a[l] */
+    swap(array[k], array[l]);
+    /* 4. Reverse sequence from a[k + 1] up to the final element */
+    for (l = len - 1, k++; k < l; k++, l--)
+        swap(array[k], array[l]);
+    return 1;
+}
+
+static void dup_program(program_t *from, program_t *to)
+{
+    *to = *from;
+}
+
+static int run(program_t *p)
 {
     int out = -1;
     while (1) {
@@ -90,7 +131,7 @@ static int run(program_t *p, int in)
                 poke(p, p->cur, 3, peek(p, p->cur, 1) *  peek(p, p->cur, 2));
                 break;
             case INP:
-                poke(p, p->cur, 1, in);
+                poke(p, p->cur, 1, p->input[p->curinput++]);
                 break;
             case OUT:
                 out = peek(p, p->cur, 1);
@@ -132,15 +173,20 @@ static int usage(char *prg)
 int main(int ac, char **av)
 {
     int opt, part = 1, in = -1;
-    program_t p = { 0 };
+    program_t p = { 0 }, p1;
+    int phase[] = {0, 1, 2, 3, 4};
 
-    while ((opt = getopt(ac, av, "d:p:i:")) != -1) {
+    while ((opt = getopt(ac, av, "d:p:i:o:")) != -1) {
         switch (opt) {
             case 'd':
                 debug_level_set(atoi(optarg));
                 break;
             case 'i':
-                in = atoi(optarg);
+                p.input[p.lastinput++] = atoi(optarg);
+                break;
+            case 'o':
+                for (ulong i = 0; i < strlen(optarg); ++i)
+                    phase[i] = optarg[i] - '0';
                 break;
             case 'p':                             /* 1 or 2 */
                 part = atoi(optarg);
@@ -152,11 +198,32 @@ int main(int ac, char **av)
         }
     }
 
+    for (int i = 0; i < 5; ++i)
+        printf("phase[%d]=%d\n", i, phase[i]);
+    parse(&p);
+    int out, max = 0;
+    do {
+        out = 0;
+        for (int i = 0; i < 5; ++i) {
+            dup_program(&p, &p1);
+            p1.input[p1.lastinput++] = phase[i];
+            p1.input[p1.lastinput++] = out;
+            out = run(&p1);
+        }
+        if (out > max) {
+            max = out;
+            printf("new max: %c%c%c%c%c out=%d max=%d\n", phase[0] + '0',
+                   phase[1] + '0', phase[2] + '0', phase[3] + '0', phase[4] + '0',
+                   out, max);
+        }
+    } while (permute_next(5, phase));
+
+    exit(0);
     if (optind < ac)
         return usage(*av);
     if (in == -1)
         in = part == 1? 1: 5;
     parse(&p);
-    printf("%s : res=%d\n", *av, run(&p, in));
+    printf("%s : res=%d\n", *av, run(&p));
     exit (0);
 }