package com.company;

import java.io.*;
import java.util.Scanner;

public class A {

    public static int[] method01(File file){
        System.out.println("請(qǐng)輸入少于100個(gè)數(shù)：");
        Scanner sc = new Scanner(System.in);
        String str = sc.next().toString();//輸入字符串  例如輸入：1,-5,9,-2,3
        String[] s = str.split(",");//以符號(hào)“,”為分割線，將分割后的內(nèi)容一次存入字符數(shù)組s中 例如：此時(shí)字符串?dāng)?shù)組s中的內(nèi)容為：{"1","-5","9","-2","3"}，字符串?dāng)?shù)組長(zhǎng)度為5
        int[] array = new int[s.length];//生成一個(gè)與字符數(shù)組同等長(zhǎng)度的整型數(shù)組，用于存儲(chǔ)將字符串轉(zhuǎn)換為整型的內(nèi)容
        if(s.length >= 100){
            System.out.println("你輸入的數(shù)多于100個(gè)！");
            return null;
        }
        System.out.println("你輸入的數(shù)組是：");
        for (int i = 0;i < s.length;i++){
            array[i] = Integer.parseInt(s[i]);//這一步是逐一將字符串轉(zhuǎn)化為整型，以便于返回值的返回 例如：此時(shí)的array數(shù)組的內(nèi)容為：{1,-5,9,-2,3}
            System.out.print(s[i]+" ");
        }
        System.out.println();
        //進(jìn)入寫(xiě)操作的函數(shù)內(nèi)
        method02(file,str);
        return array;//將處理好的數(shù)組返回給調(diào)用者
    }

    public static void method02(File file,String str){
        BufferedWriter out = null;
        try{
            /*
            FileOutputStream fos = new FileOutputStream(file,true);
            OutputStreamWriter osw = new OutputStreamWriter(fos);
            out = new BufferedWriter(osw);
             */
            out = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(file,true)));
            out.write(str+"\r\n");
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                out.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    public static void main(String[] args){
        File file = new File("D:\\IntelliJIDEA2019\\javaProject1\\src\\com\\company\\a.txt");//在指定路徑下生成一個(gè)a.txt
        int[] array = null;
        array = method01(file);
        if(array != null){
            B b = new B();
            b.MSA(array,array.length);//最后調(diào)用核心算法實(shí)現(xiàn)功能
        }
    }
}

package com.company;

public class B {
    public void MSA(int[] a,int len){
        int cur = 0;
        int max1 = a[0];
        int start = 0;
        int end = 0;
        for (int i = 0;i < len;i++){
            if(cur < 0){
                cur = 0;
                start = i;
                end = i;
            }
            cur += a[i];
            if(cur > max1){
                max1 = cur;
                end = i;
            }
        }
        System.out.print("最大字串為："+max1+"，下標(biāo)從"+start+"到"+end+"(從0開(kāi)始)");
    }
}