From 62c8a6c887809641c4fd6f21cd24b0b26aae48e8 Mon Sep 17 00:00:00 2001
From: Bond_009 <bond.009@outlook.com>
Date: Thu, 10 Dec 2020 16:02:24 +0100
Subject: Optimize day 10

---
 10/part1.c | 19 ++++++++-----------
 10/part2.c | 31 +++++++++++++++----------------
 utils.h    |  7 +++++++
 3 files changed, 30 insertions(+), 27 deletions(-)
 create mode 100644 utils.h

diff --git a/10/part1.c b/10/part1.c
index 9b44cf5..f5a700e 100644
--- a/10/part1.c
+++ b/10/part1.c
@@ -11,18 +11,16 @@ void insert_value_sorted(int *list, size_t *size, int value)
     long long low = 0, high = *size;
     while (low < high) {
         int m = low + (high - low) / 2;
-        if (list[m] == value) {
-            /* Name already exists,
-                return pointer to the already existsing string and free the new one.
-            */
-            return;
-        }
-        else if (list[m] < value) {
+        if (list[m] < value) {
             low = m + 1;
         }
-        else {
+        else if (list[m] > value) {
             high = m;
         }
+        else {
+            // Value already exists in the list
+            return;
+        }
     }
 
     for (long long i = *size - 1; i >= low; i--) {
@@ -33,7 +31,7 @@ void insert_value_sorted(int *list, size_t *size, int value)
     list[low] = value;
 }
 
-int bags_count(const char *filename)
+int solve(const char *filename)
 {
     FILE *file = fopen(filename, "r");
 
@@ -44,7 +42,6 @@ int bags_count(const char *filename)
     size_t input_size = 1; // 0 is our start value
 
     while (fgets(buffer, 128, file)) {
-        puts(buffer);
         insert_value_sorted(input, &input_size, atoi(buffer));
     }
 
@@ -69,5 +66,5 @@ int bags_count(const char *filename)
 
 int main(int argc, char *argv[])
 {
-    printf("%i\n", bags_count(argv[argc - 1]));
+    printf("%i\n", solve(argv[argc - 1]));
 }
diff --git a/10/part2.c b/10/part2.c
index bd5d22c..392cf0a 100644
--- a/10/part2.c
+++ b/10/part2.c
@@ -4,6 +4,8 @@
 #include <malloc.h>
 #include <string.h>
 
+#include "../utils.h"
+
 #define MAX_INPUT_LEN 128
 
 void insert_value_sorted(int *list, size_t *size, int value)
@@ -11,18 +13,16 @@ void insert_value_sorted(int *list, size_t *size, int value)
     long long low = 0, high = *size;
     while (low < high) {
         int m = low + (high - low) / 2;
-        if (list[m] == value) {
-            /* Name already exists,
-                return pointer to the already existsing string and free the new one.
-            */
-            return;
-        }
-        else if (list[m] < value) {
+        if (list[m] < value) {
             low = m + 1;
         }
-        else {
+        else if (list[m] > value) {
             high = m;
         }
+        else {
+            // Value already exists in the list
+            return;
+        }
     }
 
     for (long long i = *size - 1; i >= low; i--) {
@@ -38,23 +38,22 @@ uint64_t pos_seq(int *input, size_t input_size)
     const static int TRIB[] = { 1, 1, 2, 4, 7 };
     int con = 0;
     uint64_t res = 1;
-
-    for (size_t i = 1; i < input_size; i++)
-    {
-        int diff = input[i] - input[i - 1];
-        if (diff == 1) {
+    int *prev = input;
+    int *cur = input + 1;
+    do {
+        if (likely(*cur - *prev == 1)) {
             con++;
         }
         else {
             res *= TRIB[con];
             con = 0;
         }
-    }
+    } while (++prev && ++cur < input + input_size);
 
     return res;
 }
 
-size_t bags_count(const char *filename)
+uint64_t solve(const char *filename)
 {
     FILE *file = fopen(filename, "r");
 
@@ -78,5 +77,5 @@ size_t bags_count(const char *filename)
 
 int main(int argc, char *argv[])
 {
-    printf("%zu\n", bags_count(argv[argc - 1]));
+    printf("%lu\n", solve(argv[argc - 1]));
 }
diff --git a/utils.h b/utils.h
new file mode 100644
index 0000000..db6b5de
--- /dev/null
+++ b/utils.h
@@ -0,0 +1,7 @@
+#ifndef AOC_UTILS_H
+#define AOC_UTILS_H
+
+#define likely(x)       __builtin_expect((x), 1)
+#define unlikely(x)     __builtin_expect((x), 0)
+
+#endif
-- 
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