117 lines
3.0 KiB
Python
117 lines
3.0 KiB
Python
# Programs are to validate JSON according to the JSON spec (https://www.json.org/), with the exception that you may assume that the string will consist entirely of the classic printable ASCII characters (codepoints 32-127, horizontal tabs, and newlines).
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# You may additionally assume that the input will not be nested more than 16 levels.
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def entry(string):
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string = string.strip()
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if len(string) == 0:
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return True
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if string[0] == '{':
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return object(string)
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elif string[0] == '[':
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return array(string)
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elif string[0] in '-0123456789':
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return number(string)
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elif string[0] == '"':
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return string(string)
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else:
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return False
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def object(string):
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if string[0] != '{':
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return False
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string = string[1:]
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if string[0] == '}':
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return True
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string = string.strip()
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if string[0] != '"':
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return False
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string = string[1:]
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if string[0] != ':':
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return False
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string = string[1:]
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string = string.strip()
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if not entry(string):
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return False
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string = string.strip()
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if string[0] == '}':
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return True
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if string[0] != ',':
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return False
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string = string[1:]
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string = string.strip()
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if not object(string):
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return False
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string = string.strip()
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if string[0] != '}':
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return False
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return True
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def array(string):
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if string[0] != '[':
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return False
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string = string[1:]
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if string[0] == ']':
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return True
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string = string.strip()
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if not entry(string):
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return False
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string = string.strip()
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if string[0] == ']':
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return True
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if string[0] != ',':
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return False
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string = string[1:]
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string = string.strip()
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if not array(string):
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return False
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string = string.strip()
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if string[0] != ']':
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return False
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return True
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def number(string):
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if string[0] not in '-0123456789':
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return False
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string = string[1:]
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if string[0] == '.':
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string = string[1:]
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if string[0] not in '0123456789':
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return False
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string = string[1:]
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while string[0] in '0123456789':
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string = string[1:]
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if string[0] not in '0123456789':
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return False
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string = string[1:]
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if string[0] not in 'eE':
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return False
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string = string[1:]
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if string[0] not in '+-':
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return False
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string = string[1:]
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if string[0] not in '0123456789':
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return False
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string = string[1:]
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while string[0] in '0123456789':
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string = string[1:]
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return True
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def string(string):
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if string[0] != '"':
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return False
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string = string[1:]
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while string[0] != '"':
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if string[0] == '\\':
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string = string[1:]
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if string[0] not in '"\\/bfnrt':
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return False
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string = string[1:]
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else:
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string = string[1:]
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return True
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def main():
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string = input()
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print(entry(string))
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if __name__ == "__main__":
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main() |