content.swift

	struct PostContent: Codable {
		struct Paragraph: Codable {
			let id: String
			let text: String
		}
		struct Section: Codable {
			let id: String
			let startIndex: Int
		}
		var paragraphs: [Paragraph]
		var sections: [Section]
	}
	
	struct Delta: Codable {
		struct Paragraph: Codable {
			let text: String
		}
		
		let type: String
		let paragraphIndex: Int
		let paragraph: Paragraph?
	}


	func solution(postContentString: String, deltasString: String) -> String {
		let postContentData = postContentString.data(using: .utf8)!
		let deltasData = deltasString.data(using: .utf8)!
		
		let decoder = JSONDecoder()
		let postContent = try! decoder.decode(PostContent.self, from: postContentData)
		let deltas = try! decoder.decode([Delta].self, from: deltasData)
		
		var paraCnt = 0
		let postContentParagraphs = postContent.paragraphs
		let postContentSections = postContent.sections
		var newParagraphs = PostContent.init(paragraphs: postContentParagraphs, sections: postContentSections)
		for post in postContent.paragraphs {
		}
		
		// writing data to json
		let jsonData = try! JSONEncoder().encode(newParagraphs)
		let jsonString = String(data: jsonData, encoding: .utf8)!
		return solution2(postContentString: jsonString)
	}

	override func viewDidLoad() {
		let filePath = Bundle.main.url(forResource: "testjson", withExtension: "json")
		do {
			print(solution(postContentString: "{\"paragraphs\": [{\"id\": \"aaa\",\"text\": \"aaa\"},{\"id\": \"bbb\",\"text\": \"bbb\"},{\"id\": \"ccc\",\"text\": \"ccc\"},{\"id\": \"ddd\",\"text\": \"ddd\"},{\"id\": \"eee\",\"text\": \"eee\"},{\"id\": \"fff\",\"text\": \"fff\"}],\"sections\": [{\"id\": \"s0\",\"startIndex\": 0},{\"id\": \"s1\",\"startIndex\": 2},{\"id\": \"s2\",\"startIndex\": 4}]}", deltasString: "[{\"type\": \"deleteParagraph\",\"paragraphIndex\": 1}, {\"type\": \"deleteParagraph\",\"paragraphIndex\": 1}]"))
		} catch {
			print("error reading file")
		}
	}