Q001_让奶牛飞_solution

[atomiCat]

Question_ID: Q001_让奶牛飞_solution

Language: java

Time Cost: 90-mins

Time Complexity: O(n)

Solution

1.遍历字符串，每次打印一行 2.tabNum记录当前行应该有多少个tab，遇到开始标签tabNum+1，遇到结束标签tabNum-1

My Code

public class Main {
    public static void main(String[] a) {
        String s = "aa<a>123<b><c/>456<c/></b></a>aa";
        for (int i = 0, length = s.length(), tabNum = 0; i < length; ) {
            int end;
            if (s.charAt(i) == '<') {
                end = indexOf(s, ">", i, length);
                if (s.charAt(i + 1) == '/')
                    print(s.substring(i, ++end), --tabNum);
                else if (s.charAt(end - 1) == '/')
                    print(s.substring(i, ++end), tabNum);
                else print(s.substring(i, ++end), tabNum++);
            } else {
                end = indexOf(s, "<", i, length);
                print(s.substring(i, end), tabNum);
            }
            i = end;
        }
    }

    static void print(String s, int tabNum) {
        StringBuilder sb = new StringBuilder("\r\n");
        while (tabNum-- > 0)
            sb.append("    ");
        sb.append(s);
        System.out.print(sb);
    }

    static int indexOf(String s, String sub, int from, int ifNotFound) {
        int i = s.indexOf(sub, from);
        return i < 0 ? ifNotFound : i;
    }
}