Extract permutation iterator

Author: ishanpranav

Makefile

@@ -8,7 +8,6 @@ all: \
 day02a day02b \
 day05a day05b \
 day07a day07b \
-day08a day08b \
 day09a day09b \
 day10a \
 day11a day11b \
@@ -31,13 +30,16 @@ emulator: lib/emulator.h lib/emulator.c
 
 parser: lib/parser.h lib/parser.c
 $(CC) $(CFLAGS) -c lib/parser.c -o parser.o
-
+
 emulate: tools/emulate.c emulator parser
 $(CC) $(CFLAGS) $< -o emulate.o emulator.o parser.o
 
 intcode: tools/intcode.c emulator parser
 $(CC) $(CFLAGS) $< -o intcode.o emulator.o parser.o
 
+permutation_iterator: lib/permutation_iterator.h lib/permutation_iterator.c
+$(CC) $(CFLAGS) -c lib/permutation_iterator.c -o permutation_iterator.o
+
 day02a: src/day02a.c emulator parser
 $(CC) $(CFLAGS) $< -o $@.o emulator.o parser.o
 
@@ -50,17 +52,11 @@ day05a: src/day05a.c emulator parser
 day05b: src/day05b.c emulator parser
 $(CC) $(CFLAGS) $< -o $@.o emulator.o parser.o
 
-day07a: src/day07a.c emulator parser
-$(CC) $(CFLAGS) $< -o $@.o emulator.o parser.o
+day07a: src/day07a.c emulator parser permutation_iterator
+$(CC) $(CFLAGS) $< -o $@.o emulator.o parser.o permutation_iterator.o
 
-day07b: src/day07b.c emulator parser
-$(CC) $(CFLAGS) $< -o $@.o emulator.o parser.o
-
-day08a: src/day08a.c
-$(CC) $(CFLAGS) $< -o $@.o
-
-day08b: src/day08b.c
-$(CC) $(CFLAGS) $< -o $@.o
+day07b: src/day07b.c emulator parser permutation_iterator
+$(CC) $(CFLAGS) $< -o $@.o emulator.o parser.o permutation_iterator.o
 
 day09a: src/day09a.c
 $(CC) $(CFLAGS) $< -o $@.o $(LIBM)

lib/permutation_iterator.c

@@ -0,0 +1,54 @@
+// Author: Ishan Pranav
+// Copyright (c) 2023 Ishan Pranav
+// Licensed under the MIT license.
+
+#include "permutation_iterator.h"
+
+static void swap(int* p, int* q)
+{
+ int swap = *p;
+
+ *p = *q;
+ *q = swap;
+}
+
+void permutation_begin(int* values, int length, PermutationIterator iterator)
+{
+ iterator->end = false;
+ iterator->length = length;
+ iterator->values = values;
+}
+
+void permutation_next(PermutationIterator iterator)
+{
+ int last = iterator->length - 1;
+
+ while (last > 0 && iterator->values[last - 1] >= iterator->values[last])
+ {
+ last--;
+ }
+
+ if (last > 0)
+ {
+ int index = iterator->length - 1;
+
+ while (index > last && 
+ iterator->values[index] <= iterator->values[last - 1])
+ {
+ index--;
+ }
+
+ swap(iterator->values + last - 1, iterator->values + index);
+ }
+
+ int max = (iterator->length - last) / 2;
+
+ for (int index = 0; index < max; index++)
+ {
+ swap(
+ iterator->values + last + index,
+ iterator->values + iterator->length - 1 - index);
+ }
+
+ iterator->end = !last;
+}

lib/permutation_iterator.h

@@ -0,0 +1,17 @@
+// Author: Ishan Pranav
+// Copyright (c) 2023 Ishan Pranav
+// Licensed under the MIT license.
+
+#include <stdbool.h>
+
+struct PermutationIterator
+{
+ int* values;
+ int length;
+ bool end;
+};
+
+typedef struct PermutationIterator* PermutationIterator;
+
+void permutation_begin(int* values, int length, PermutationIterator iterator);
+void permutation_next(PermutationIterator iterator);

src/day05a.c

@@ -4,7 +4,6 @@
 
 // Sunny with a Chance of Asteroids Part 1
 
-#include <stdlib.h>
 #include <time.h>
 #include "../lib/emulator.h"
 #include "../lib/parser.h"

src/day05b.c

@@ -4,7 +4,6 @@
 
 // Sunny with a Chance of Asteroids Part 2
 
-#include <stdlib.h>
 #include <time.h>
 #include "../lib/emulator.h"
 #include "../lib/parser.h"

src/day07a.c

@@ -4,73 +4,15 @@
 
 // Amplification Circuit Part 1
 
-#include <stdbool.h>
-#include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include "../lib/emulator.h"
 #include "../lib/parser.h"
+#include "../lib/permutation_iterator.h"
 #define INPUTS 2
 #define MEMORY 4096
 #define OUTPUTS 1
 
-struct PermutationIterator
-{
- int* values;
- int length;
- bool end;
-};
-
-typedef struct PermutationIterator* PermutationIterator;
-
-static void swap(int* p, int* q)
-{
- int swap = *p;
-
- *p = *q;
- *q = swap;
-}
-
-void permutation_begin(int* values, int length, PermutationIterator iter)
-{
- iter->end = false;
- iter->length = length;
- iter->values = values;
-}
-
-void permutation_next(PermutationIterator iter)
-{
- int last = iter->length - 1;
-
- while (last > 0 && iter->values[last - 1] >= iter->values[last])
- {
- last--;
- }
-
- if (last > 0)
- {
- int index = iter->length - 1;
-
- while (index > last && iter->values[index] <= iter->values[last - 1])
- {
- index--;
- }
-
- swap(iter->values + last - 1, iter->values + index);
- }
-
- int max = (iter->length - last) / 2;
-
- for (int index = 0; index < max; index++)
- {
- swap(
- iter->values + last + index,
- iter->values + iter->length - 1 - index);
- }
-
- iter->end = !last;
-}
-
 int main()
 {
  Word max = 0;

src/day07b.c

@@ -4,12 +4,11 @@
 
 // Amplification Circuit Part 2
 
-#include <stdbool.h>
-#include <stdlib.h>
 #include <string.h>
 #include <time.h>
 #include "../lib/emulator.h"
 #include "../lib/parser.h"
+#include "../lib/permutation_iterator.h"
 #define EMULATOR_QUEUE_CAPACITY 5
 #define INPUTS 2
 #define MEMORY 4096
@@ -22,63 +21,7 @@ struct EmulatorQueue
  int last;
 };
 
-struct PermutationIterator
-{
- int* values;
- int length;
- bool end;
-};
-
 typedef struct EmulatorQueue* EmulatorQueue;
-typedef struct PermutationIterator* PermutationIterator;
-
-static void swap(int* p, int* q)
-{
- int swap = *p;
-
- *p = *q;
- *q = swap;
-}
-
-void permutation_begin(int* values, int length, PermutationIterator iter)
-{
- iter->end = false;
- iter->length = length;
- iter->values = values;
-}
-
-void permutation_next(PermutationIterator iter)
-{
- int last = iter->length - 1;
-
- while (last > 0 && iter->values[last - 1] >= iter->values[last])
- {
- last--;
- }
-
- if (last > 0)
- {
- int index = iter->length - 1;
-
- while (index > last && iter->values[index] <= iter->values[last - 1])
- {
- index--;
- }
-
- swap(iter->values + last - 1, iter->values + index);
- }
-
- int max = (iter->length - last) / 2;
-
- for (int index = 0; index < max; index++)
- {
- swap(
- iter->values + last + index,
- iter->values + iter->length - 1 - index);
- }
-
- iter->end = !last;
-}
 
 void emulator_queue(EmulatorQueue instance)
 {