advent2021

commit 5cb3777952b8ebf00878668998d91b0db99535ae
parent 12cad2011c8345dc17e8f5da903c3169611f3d83
Author: bsandro <[email protected]>
Date:   Tue,  7 Dec 2021 15:16:18 +0200

Day 07, puzzle 2

Diffstat:
M
day07/Makefile
 | 
4
++--
M
day07/puzzle.c
 | 
13
++++++++++++-

2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/day07/Makefile b/day07/Makefile
@@ -3,8 +3,8 @@ CC=cc
 SRC=$(wildcard *.c)
 DEPS:=$(wildcard *.h)
 OBJ:=$(SRC:.c=.o)
-
-CFLAGS=-O2 -std=c99 -Werror -Wall -Wextra -I. -I../common
+CFLAGS=-O0 -g -std=c99 -Werror -Wall -Wextra -I. -I../common
+LDFLAGS=-lc -lm
 
 all: $(NAME)
 
diff --git a/day07/puzzle.c b/day07/puzzle.c
@@ -8,6 +8,7 @@
 #include <stdbool.h>
 #include <assert.h>
 #include <time.h>
+#include <math.h>
 
 #include "util.h"
 
@@ -42,6 +43,7 @@ void puzzle(const char *filename, size_t *result1, size_t *result2) {
 
 	qs((int *)numbers.data, 0, numbers.count - 1);
 
+	// median average
 	size_t index = numbers.count / 2;
 	int *data = (int *)numbers.data;
 	int mid = data[index];
@@ -49,7 +51,16 @@ void puzzle(const char *filename, size_t *result1, size_t *result2) {
 		*result1 += abs(data[i] - mid);
 	}
 
-	*result2 = 0;
+	// geometric average
+	double sum = 0;
+	for (size_t i = 0; i < numbers.count; ++i) {
+		sum += data[i];
+	}
+	int avg = floor((sum + 1) / (double)numbers.count);
+	for (size_t i = 0; i < numbers.count; ++i) {
+		int dist = abs(data[i] - avg);
+		*result2 += dist * (1 + dist) / 2;
+	}
 
 	// mutiny! ignoring feof/ferror.
 	free(numbers.data);