Big integer addition

JAVA Implementation

Package classic; import Java. math. biginteger; import Java. util. regEx. matcher; import Java. util. regEx. pattern; public class bigintegeraddition {/*** @ Param ARGs */public static void main (string [] ARGs) {// todo auto-generated method stub string x = "12314123112313"; string y = "10889129018390813908"; string Z; biginteger A = new biginteger (X ); biginteger B = new biginteger (y); Z =. add (B ). tostring (); system. out. P Rintln (z); system. out. println (add (x, y);} public static int [] tointarray (string Str) {int length = Str. length (); int [] A = new int [length]; for (INT I = 0; I <length; I ++) A [I] = Str. charat (I)-'0'; return a;} public static string add (string a, string B) {if (a = NULL | B = NULL) return NULL; If (! Isnumeric (a) |! Isnumeric (B) return NULL; if (. equals ("0") return B; If (B. equals ("0") return a; if (. length () = B. length () {return addhelp (a, B);} else if (. length ()> B. length () {string x = A; string y = addzerotofirst (B,. length (); Return addhelp (x, y);} else {string y = B; string x = addzerotofirst (A, B. length (); Return addhelp (x, y) ;}} public static string addhelp (string a, string B) {int length =. length (); int [] x = tointarray (a); int [] Y = tointarray (B); int [] Z = new int [Length + 1]; int temp; int diff = 0; For (INT I = length; I> 0; I --) {temp = x [I-1] + Y [I-1] + diff; Z [I] = TEMP % 10; diff = temp/10;} Z [0] = diff; stringbuilder sb = new stringbuilder (); For (INT I = 1-diff; I <= length; I ++) {sb. append (Z [I]);} return sb. tostring ();} public static string addzerotofirst (string STR, int N) {stringbuilder sb = new stringbuilder (); int length = Str. length (); int diff = N-length; while (diff> 0) {sb. append ("0"); diff --;} sb. append (STR); return sb. tostring ();} public static Boolean isnumeric (string Str) {pattern P = pattern. compile ("[0-9] *"); matcher M = P. matcher (STR); Return M. matches ();}}

 

Big integer addition