父字符串顺序匹配子字符串

StringUtil.java

/**
 * String Utility
 *
 * @author yanganyu
 * @date 2019/3/18 14:31
 */
public class StringUtil {
	private StringUtil() {
	}

	/**
	 * 父字符串顺序匹配子字符串
	 * <pre>
	 *     子字符串只要按顺序出现在父字符串中就能匹配，中间缺几个字符不影响匹配
	 *     例子：
	 *     		inOrderMatches("abcdefg", "cfg") is true
	 *     		inOrderMatches("abcdefg", "ad")	is true
	 *     		inOrderMatches("abcdefg", "acg") is true
	 *     		inOrderMatches("abcdefg", "efc") is false
	 * </pre>
	 *
	 * @param parentStr parentStr 父字符串
	 * @param childStr  childStr 子字符串
	 * @return boolean
	 * @author yanganyu
	 * @date 2019/3/18 14:19
	 */
	public static boolean inOrderMatches(String parentStr, String childStr) {
		if (parentStr == null || childStr == null) {
			return false;
		}
		char[] parentChars = parentStr.toCharArray();
		char[] childChars = childStr.toCharArray();
		int parentCharsPos = 0;
		for (int i = 0; i < childChars.length; i++) {
			boolean flag = false;
			for (; parentCharsPos < parentChars.length; parentCharsPos++) {
				flag = childChars[i] == parentChars[parentCharsPos];
				if (flag) {
					parentCharsPos = parentCharsPos + 1;
					break;
				}
			}
			// parentChars遍历完
			if (parentCharsPos == parentChars.length) {
				// childChars没遍历判断完
				if (i < childChars.length - 1) {
					return false;
				} else {
					return flag;
				}
			}
		}
		return true;
	}
}