Day 2, 2017 - Parts I & II

Author: scottshepard

2017/day02.py

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+# --- Day 2: Corruption Checksum ---
+#
+# As you walk through the door, a glowing humanoid shape yells in your direction. 
+# "You there! Your state appears to be idle. Come help us repair the corruption 
+# in this spreadsheet - if we take another millisecond, we'll have to display an 
+# hourglass cursor!"
+#
+# The spreadsheet consists of rows of apparently-random numbers. To make sure 
+# the recovery process is on the right track, they need you to calculate the 
+# spreadsheet's checksum. For each row, determine the difference between the 
+# largest value and the smallest value; the checksum is the sum of all of these 
+# differences.
+#
+# For example, given the following spreadsheet:
+#
+# 5 1 9 5
+# 7 5 3
+# 2 4 6 8
+# The first row's largest and smallest values are 9 and 1, and their difference is 8.
+# The second row's largest and smallest values are 7 and 3, and their difference is 4.
+# The third row's difference is 6.
+# In this example, the spreadsheet's checksum would be 8 + 4 + 6 = 18.
+#
+# What is the checksum for the spreadsheet in your puzzle input?
+# Answer: 41887
+# 
+# --- Part Two ---
+#
+# "Great work; looks like we're on the right track after all. 
+# Here's a star for your effort." However, the program seems a little worried. 
+# Can programs be worried?
+#
+# "Based on what we're seeing, it looks like all the User wanted is some 
+# information about the evenly divisible values in the spreadsheet. 
+# Unfortunately, none of us are equipped for that kind of calculation - 
+# most of us specialize in bitwise operations."
+#
+# It sounds like the goal is to find the only two numbers in each row where one 
+# evenly divides the other - that is, where the result of the division 
+# operation is a whole number. They would like you to find those numbers on 
+# each line, divide them, and add up each line's result.
+#
+# For example, given the following spreadsheet:
+#
+# 5 9 2 8
+# 9 4 7 3
+# 3 8 6 5
+# In the first row, the only two numbers that evenly divide are 8 and 2; 
+# the result of this division is 4.
+# In the second row, the two numbers are 9 and 3; the result is 3.
+# In the third row, the result is 2.
+# In this example, the sum of the results would be 4 + 3 + 2 = 9.
+
+# What is the sum of each row's result in your puzzle input?
+# Answer: 226
+#
+# ------------------------------------------------------------------------------
+
+import os
+
+def checksum1(lines):
+    return sum([min_max_diff(line) for line in lines])
+
+def min_max_diff(line):
+    return max(line) - min(line)
+
+def checksum2(lines):
+    return sum([mod(line) for line in lines])
+
+def mod(line):
+    for n in line:
+        l2 = line.copy()
+        l2.remove(n)
+        for n2 in l2:
+            if n % n2 == 0:
+                return int(n / n2)
+
+if __name__ == '__main__':
+    file_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), "inputs/day02.txt")
+    f = open(file_path)
+    data = f.read().split('\n')
+    data = [[int(e) for e in line.split()] for line in data]
+    print(checksum1(data))
+    print(checksum2(data))

2017/inputs/day02.txt

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+116	1259	1045	679	1334	157	277	1217	218	641	1089	136	247	1195	239	834
+269	1751	732	3016	260	6440	5773	4677	306	230	6928	7182	231	2942	2738	3617
+644	128	89	361	530	97	35	604	535	297	599	121	567	106	114	480
+105	408	120	363	430	102	137	283	123	258	19	101	181	477	463	279
+873	116	840	105	285	238	540	22	117	125	699	953	920	106	113	259
+3695	161	186	2188	3611	2802	157	2154	3394	145	2725	1327	3741	2493	3607	4041
+140	1401	110	119	112	1586	125	937	1469	1015	879	1798	122	1151	100	926
+2401	191	219	607	267	2362	932	2283	889	2567	2171	2409	1078	2247	2441	245
+928	1142	957	1155	922	1039	452	285	467	305	506	221	281	59	667	232
+3882	1698	170	5796	2557	173	1228	4630	174	3508	5629	4395	180	5100	2814	2247
+396	311	223	227	340	313	355	469	229	162	107	76	363	132	453	161
+627	1331	1143	1572	966	388	198	2068	201	239	176	1805	1506	1890	1980	1887
+3390	5336	1730	4072	5342	216	3823	85	5408	5774	247	5308	232	256	5214	787
+176	1694	1787	1586	3798	4243	157	4224	3603	2121	3733	851	2493	4136	148	153
+2432	4030	3397	4032	3952	2727	157	3284	3450	3229	4169	3471	4255	155	127	186
+919	615	335	816	138	97	881	790	855	89	451	789	423	108	95	116

2017/inputs/day02_test.txt

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+5 1 9 5
+7 5 3
+2 4 6 8

2017/inputs/day02_test2.txt

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+5 9 2 8
+9 4 7 3
+3 8 6 5