Subtract large numbers

Topic Description:

input: Two positive large numbers

output: Two difference in large numbers

Code implementation:

Import java.util.ArrayList;
Import java.util.List;

Import Java.util.Scanner; /** * @author Njupt * Two number of Zhengda */public class Bignumsub {public static void main (string[] args) {Scanner cin=new
		Scanner (system.in);
			String minuend;//is a meiosis string meiosis;//the difference;//difference while (Cin.hasnext ()) {minuend=cin.next ();
			Meiosis=cin.next (); if (!valid (minuend) | |!
			Valid (meiosis))//legality verification return;
			Difference=bignumsub (minuend,meiosis);
		SYSTEM.OUT.PRINTLN (difference); }/** * @param minuend Bing * @param meiosis meiosis * @return Difference difference * * 1. Determining the size of meiosis and meiosis * (1): meiosis minu The number of digits of end is greater than the number of digits of meiosis, then the direct subtraction * (2): The number of bits in the meiotic minuend is less than that of meiosis, and the result plus-(minus) * (3): The number of digits in the meiotic minuend equals the number of meiosis meiosis, Determine the size of the two: * a:minuend>=meiosis, then directly subtract * b:minuend<meiosis, swap subtract, the result plus-(minus) */private static String Bignu Msub (String minuend, string meiosis) {int minlen=minuend.length ();//Bing length int meilen=meiosis.length ();/length of meiosis bo Olean addsign=false;//Whether to exchange the meiosis and meiosis String difference;//results if (minlen<meilen) {addsign=true;
			String Temp=minuend;
			Minuend=meiosis;
		Meiosis=temp;
			}else if (Minlen==meilen) {//two digits equal//Judge size int Re=judge (minuend,meiosis);
				if (re==-1)//less than, to exchange {addsign=true;
				String Temp=minuend;
				Minuend=meiosis;
			Meiosis=temp;
			}else if (re==0) {return "0";
		}//Subtract difference=sub (minuend,meiosis);
		
		if (addsign) return "-" +difference;
	return difference;
	/** * @param minuend * @param meiosis * @return Difference * Two number of large numbers, here according to the mathematical size has been meiosis minuend>=meiosis * * private static string sub (string minuend, string meiosis) {int minlen=minuend.length ();//Bing length int meilen=meiosis.le Ngth ()//meiosis length int dif=minlen-meilen;//Two number of Boolean borrow=false;//borrow list<integer> list=new arraylist<
		Integer> ()//place each phase minus the result int i=meilen-1;
		int j=i+dif;
		int min=0;
		int mei=0; for (; I >=0; J--, i--) {min=integer.valueof (Minuend.cha)RAt (j))-48;
			Mei=integer.valueof (Meiosis.charat (i))-48;
			
			int result=0;
			if (borrow) {//Borrow condition min=min-1;
			} if (Min>=mei) {Result=min-mei;
				}else{//need borrow Result=min+10-mei;
			Borrow=true;
		} list.add (Result);
			Log the remaining Bing bits for (; j>=0; j--) {min=integer.valueof (Minuend.charat (j))-48;
				if (borrow) {//borrow min=min-1 last time;
			Borrow=false;
		} list.add (min);
		} StringBuilder sb=new StringBuilder ();
		Note here to remove the preceding 0-bit boolean remove=true;
			for (int k=list.size () -1;k>=0;k--) {int re=list.get (k); if (re!=0| |
				Remove==false) {sb.append (re);
			Remove=false;
	} return sb.tostring (); /** * @param minuend * @param meiosis * @return result * To determine the mathematical significance of the large number of equal digits in relation to the size/private static int judge (
		String minuend, String meiosis) {int result=0;//default Bing greater than the meiotic int len=minuend.length ();
		int i=0;
				for (; i<len;i++) {if (Minuend.charat (i) >meiosis.charat (i)) {//greater than result=1;
			return result; }elsE if (Minuend.charat (i) <meiosis.charat (i)) {//less than result=-1;
			return result;
	} return result; }//input legality validation private static Boolean valid (String number) {if (null==number&& "". Equals (number)) return Fals
		E
		Char[] Chararr=number.tochararray ();
		if (chararr[0]== ' 0 ')//The first character cannot be 0 return false;
			for (int i = 1; i < chararr.length i++) {//each character is between 0 and 9 Char temp=chararr[i]; if (temp< ' 0 ' | |
		Temp> ' 9 ') return false;
	return true;
 }

}