2017.07.1

2017/07/1recursive-circus.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+
+if __name__ == '__main__':
+    with open('input','r',encoding='utf-8') as file:
+        all_programs = file.readlines()
+        i = 0
+        for program in all_programs:
+            program = program.split()
+            program[1] = int(program[1].strip('()'))
+            if len(program) > 2:
+                program[2] = []
+                for j in range(3, len(program)):
+                    program[2].append(program[j].strip(','))
+                program = [program[0], program[1], program[2]]
+            else:
+                program.append([])
+            all_programs[i] = program
+            i += 1
+    # at this point, each line is one program in the stack,
+    # and each line is a list of info.
+    # list[0] is the program name.
+    # list[1] is the program weight.
+    # list[2] is a list of other programs which sit directly on top.
+    # for part 1, we simply need to find the program name
+    # which exists in no other list of children!
+
+    # the datatype of all_programs is
+    # [[string,int,[string, string,...]],[string,int,[string,string,...],...]
+
+    def find_position(programs_list):
+        all_children = ['']
+        for program in programs_list:
+            if len(program) == 2:
+                program = program.append("top")
+            else:
+                children = program[2]
+                if all_children == ['']:
+                    all_children = children
+                else:
+                    all_children = all_children + children
+        # note: all_children will not have duplicates!
+        #         why? can't stand on two programs' heads at once....
+        for program in programs_list:
+            try:
+                all_children.index(program[0])
+            except ValueError:
+                program = program.append("bot")
+        for program in programs_list:
+            if len(program) == 3:
+                program = program.append("mid")
+
+    find_position(all_programs)
+
+    i = 0
+    for program in all_programs:
+        if program[3] == "bot":
+            bot_index = i
+        i += 1
+    bot_name = all_programs[bot_index][0]
+    print(bot_name)