1694. 重新格式化电话号码

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Java：while 切糖果

class Solution {public String reformatNumber(String number) {StringBuilder sb = new StringBuilder();for (int i = 0; i < number.length(); ++i) {char ch = number.charAt(i);if (Character.isDigit(ch)) {sb.append(ch);}}int n = sb.length();int pt = 0;StringBuilder ans = new StringBuilder();while (n > 0) {if (n > 4) {ans.append(sb.substring(pt, pt + 3) + "-");pt += 3;n -= 3;  // 一个步长一个步长的减小} else {if (n == 4) {ans.append(sb.substring(pt, pt + 2) + "-" + sb.substring(pt + 2, pt + 4));} else {ans.append(sb.substring(pt, pt + n));}break;}}return ans.toString();}
}

Java：自己搓的代码

class Solution {public String reformatNumber(String number) {String s1 = number.replace("-", "");String s2 = s1.replace(" ", "");System.out.println(s2);int n = s2.length();int m = n % 3;int size = 0;if (m == 0) {size = n;} else if (m == 1) {size = n - 4;} else {size = n - 2;}StringBuilder sb = new StringBuilder();for (int i = 0; i < size; i++) {sb.append(s2.charAt(i));if ((i != size-1) && (i+1) % 3 == 0) {sb.append("-");}}if (m == 1) {sb.append("-");sb.append(s2.charAt(n - 4));sb.append(s2.charAt(n - 3));sb.append("-");sb.append(s2.charAt(n - 2));sb.append(s2.charAt(n - 1));} else if (m == 2) {sb.append("-");sb.append(s2.charAt(n - 2));sb.append(s2.charAt(n - 1));}if (sb.toString().startsWith("-")) {return sb.toString().substring(1);}return sb.toString();}
}