Day 7 part 2

7/7_2.py

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+#!/usr/bin/env python
+# 2021 - Advent Of Code - 7 part 2
+
+def parse_file(file):
+    with open(file) as f:
+        line = f.readline()
+
+    list_state = [int(x) for x in line.split(',')]
+
+    return list_state
+
+
+def sum_n(n):
+    return int(n*(n+1) / 2)
+
+
+# init_state = parse_file('input_example.txt')
+init_state = parse_file('input.txt')
+nb_crabs = len(init_state)
+print(f'Initial state with {nb_crabs} crabs: {init_state}')
+
+max_h = max(init_state)
+print(f'maximum horizontal position is {max_h}')
+all_diff = [0] * max_h
+
+min_fuel = sum_n(max_h) * nb_crabs
+min_fuel_pos = 0
+for m in range(max_h):
+    list_diff = [sum_n(abs(m-x)) for x in init_state]
+    if sum(list_diff) < min_fuel:
+        min_fuel = sum(list_diff)
+        min_fuel_pos = m
+
+    all_diff[m] = list_diff
+
+print(f'min fuel {min_fuel} for position {min_fuel_pos}')