Merge pull request devcordde#35 from JohnnyJayJay/master

Add day 6 solution in C

Author: JohnnyJayJay

Day-02/c/JohnnyJayJay/Day02.c

@@ -17,7 +17,7 @@ int main(int argc, char** argv) {
  FILE* file = fopen(argv[1], "r");
  int lines = count_lines(file);
 
- db_entry entries[lines];
+ db_entry* entries = malloc(sizeof(db_entry) * lines);
  for (int i = 0; i < lines; i++) {
  int min, max;
  char c;

Day-03/c/JohnnyJayJay/Day03.c

@@ -2,14 +2,15 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <stdint.h>
 #include "../../../shared/JohnnyJayJay/aoc.h"
 
-int traverse(u_int32_t* levels, int lines, int width, int x_step, int y_step) {
+int traverse(uint32_t* levels, int lines, int width, int x_step, int y_step) {
  int x_pos = 0;
  int tree_count = 0;
  for (int i = 0; i < lines; i += y_step) {
- u_int32_t level = levels[i];
- if ((level >> (width - 1 - x_pos)) & ((u_int32_t) 1)) {
+ uint32_t level = levels[i];
+ if ((level >> (width - 1 - x_pos)) & 1) {
  tree_count++;
  }
  x_pos = (x_pos + x_step) % width;
@@ -21,9 +22,9 @@ int main(int argc, char** argv) {
  FILE* file = fopen(argv[1], "r");
  int lines = count_lines(file);
  int width = chars_until(file, '\n', 1);
- u_int32_t* levels = malloc(sizeof(u_int32_t) * lines);
+ uint32_t* levels = malloc(sizeof(uint32_t) * lines);
  for (int i = 0; i < lines; i++) {
- u_int32_t level = 0;
+ uint32_t level = 0;
  int spot;
  while ((spot = fgetc(file)) != '\n' && spot != EOF) {
  level <<= 1;
@@ -32,12 +33,12 @@ int main(int argc, char** argv) {
  levels[i] = level;
  }
 
- u_int64_t first = traverse(levels, lines, width, 3, 1);
+ uint64_t first = traverse(levels, lines, width, 3, 1);
  printf("You encounter %lu trees the first slope.\n", first);
- u_int64_t second = traverse(levels, lines, width, 1, 1);
- u_int64_t third = traverse(levels, lines, width, 5, 1);
- u_int64_t fourth = traverse(levels, lines, width, 7, 1);
- u_int64_t fiveth = traverse(levels, lines, width, 1, 2);
+ uint64_t second = traverse(levels, lines, width, 1, 1);
+ uint64_t third = traverse(levels, lines, width, 5, 1);
+ uint64_t fourth = traverse(levels, lines, width, 7, 1);
+ uint64_t fiveth = traverse(levels, lines, width, 1, 2);
  printf("The trees on all slopes multiplied together: %lu\n", first * second * third * fourth * fiveth);
 
-}
+}

Day-05/c/JohnnyJayJay/Day05.c

@@ -19,13 +19,7 @@ int find_value(char* desc, int length, char lower, char upper) {
 int intcmp(const void* one, const void* two) {
  int a = *((int*) one);
  int b = *((int*) two);
- if (a == b) {
- return 0;
- } else if (a < b) {
- return -1;
- } else {
- return 1;
- }
+ return a - b;
 }
 
 int main(int argc, char** argv) {
@@ -47,7 +41,7 @@ int main(int argc, char** argv) {
  for (int i = 0; i < lines - 1; i++) {
  int first = passes[i];
  int second = passes[i + 1];
- if (abs(first - second) == 2) {
+ if (second - first == 2) {
  own_seat_id = first + 1;
  break;
  }

Day-06/c/JohnnyJayJay/Day06.c

@@ -0,0 +1,39 @@
+// Read my README in shared/JohnnyJayJay
+
+#include <stdio.h>
+#include <stdint.h>
+#include "../../../shared/JohnnyJayJay/aoc.h"
+
+int popcount(uint32_t bits) {
+ int count;
+ for (count = 0; bits > 0; bits >>= 1) {
+ count += bits & 1;
+ }
+ return count;
+}
+
+int main(int argc, char** argv) {
+ FILE* file = fopen(argv[1], "r");
+ int groups = count_blank_lines(file) + 1;
+ int sum_1 = 0;
+ int sum_2 = 0;
+ for (int i = 0; i < groups; i++) {
+ int next;
+ uint32_t group_set_1 = 0;
+ uint32_t group_set_2 = 0xffffffff;
+ while ((next = fgetc(file)) != '\n' && next != EOF) {
+ uint32_t person_set = 0;
+ do {
+ int pos = next - 'a';
+ person_set |= 1 << pos;
+ next = fgetc(file);
+ } while (next != EOF && next != '\n');
+ group_set_1 |= person_set;
+ group_set_2 &= person_set;
+ }
+ sum_1 += popcount(group_set_1);
+ sum_2 += popcount(group_set_2);
+ }
+ printf("Sum of the group answer counts (part 1): %d\n", sum_1);
+ printf("Sum of the group answer counts (part 2): %d\n", sum_2);
+}

shared/JohnnyJayJay/aoc.h

@@ -1,5 +1,3 @@
-#include <stdio.h>
-
 int count_lines(FILE* file);
 
 int count_blank_lines(FILE* file);