The Code Interview Guide for Programmers Chapter 5 Summation of Numeric Substrings in a Binary Tree Question String

topic

字符串中数字子串的求和

java code

package com.lizhouwei.chapter5;

/**
 * @Description: 字符串中数字子串的求和
 * @Author: lizhouwei
 * @CreateDate: 2018/4/23 21:05
 * @Modify by:
 * @ModifyDate:
 */
public class Chapter5_2 {

    public int numSum(String str) {
        char[] charArr = str.toCharArray();
        int res = 0;
        int num = 0;
        int cur = 0;
        boolean posi = true;
        for (int i = 0; i < charArr.length; i++) {
            cur = charArr[i] - '0';
            if (cur < 0 || cur > 9) {
                res += num;
                num = 0;
                if (charArr[i] == '-') {
                    if (i > 0 && charArr[i - 1] == '-') {
                        posi = !posi;
                    } else {
                        posi = false;
                    }
                } else {
                    posi = true;
                }
            } else {
                num = num * 10 + (posi ? cur : -cur);
            }
        }
        res += num;
        return res;
    }

    //测试
    public static void main(String[] args) {
        Chapter5_2 chapter = new Chapter5_2();
        String str = "A--1CD---2EE33";
        System.out.println("A--1CD---2EE33中数字之和：" + chapter.numSum(str));
    }
}

result