用Java写N个数求和

测试三一直过不去，看了很多文章发现可能是因为分子分母各自相加时超过longlong的范围，以下代码是没有修改过不了测试三的代码。我通过查找分母之间的最大公倍数然后进行运算。

代码如下：

import java.util.Scanner;public class Main {public static void main(String[] args) {Main m = new Main();Scanner sc = new Scanner(System.in);sc.nextInt();sc.nextLine();String a = sc.nextLine();String [] b ;int flag = 0;//按空格拆分数据，分为String数组bb = a.split("\\s+");//按除号分开数据String [] c ;int up = 0 , down = 0;int minnumber = 0;int total = 0;for (int i = 0; i < b.length-1; i++) {c = b[i].split("/+");up = Integer.parseInt(c[0]);down = Integer.parseInt(c[1]);c = b[i+1].split("/+");minnumber = m.FindMin(down,Integer.parseInt(c[1]),flag);total = m.Addup(up,down,c,minnumber);b[i+1] = total+"/"+minnumber;}m.Print(b[b.length-1]);}//查找最小公倍数public int FindMin(int a, int b ,int flag){int min = a<b? a:b ;int max = a>b? a:b ;int minnumber = min ;while(max%min!=0){minnumber = max%min;max = min;min = minnumber;}if(flag == 0){minnumber = a * b / minnumber;return minnumber;}else {return min;}}//两个分子相加public int Addup(int ups1 ,int downs1, String [] s2 ,int minnumber){int ups2 = Integer.parseInt(s2[0]);int downs2 = Integer.parseInt(s2[1]);ups1 = ups1*(minnumber/downs1);ups2 = ups2*(minnumber/downs2);return ups1+ups2;}public void Print(String a){String [] c = a.split("/+");String b = "";int flag = 1 ;int divisor = 0;int upnumber = Integer.parseInt(c[0]);int downnumber = Integer.parseInt(c[1]);if(upnumber == 0){System.out.println("0");}else if(Math.abs(upnumber) < Math.abs(downnumber) ){divisor = FindMin(upnumber,downnumber,flag);upnumber /= divisor;downnumber /= divisor;if(upnumber < 0 && downnumber > 0 || upnumber > 0 && downnumber<0){upnumber = Math.abs(upnumber);downnumber = Math.abs(downnumber);System.out.println("-"+upnumber + "/" + downnumber);}else{System.out.println(upnumber + "/" + downnumber);}}else if(upnumber%downnumber == 0){System.out.println(upnumber/downnumber);}else{b += upnumber/downnumber;upnumber -= downnumber*(upnumber/downnumber);divisor = FindMin(upnumber,downnumber,flag);upnumber /= divisor;downnumber /= divisor;if(upnumber > 0 && downnumber > 0) {System.out.println(b + " " + upnumber + "/" + downnumber);}else if(upnumber > 0 && downnumber <0 || upnumber < 0 && downnumber >0){upnumber = Math.abs(upnumber);downnumber = Math.abs(downnumber);System.out.println(b + " " +"-"+ upnumber + "/" + downnumber);}else{upnumber = Math.abs(upnumber);downnumber = Math.abs(downnumber);System.out.println(b + " " + upnumber + "/" + downnumber);}}}
}