POJ 2389 Bull Math (large number multiplication, or Java good)

Bull Math

Time Limit: 1000MS		Memory Limit: 65536K
Total Submissions: 14252		Accepted: 7350

Description

Bulls is so much better at math than the cows. They can multiply huge integers together and get perfectly precise answers ... or so they say. Farmer John wonders if their answers is correct. Help him check the Bulls ' answers. Read in the positive integers (no more than-digits each) and compute their product. Output it as a normal number (with no extra leading zeros).

FJ asks this yourself; Don ' t use a special library function for the multiplication.

Input

* Lines 1..2:each line contains a single decimal number.

Output

* Line 1:the Exact product of the lines

Sample Input

111111111111111111111111

Sample Output

12345679011110987654321

Source

Usaco 2004 November
original title link: http://poj.org/problem?id=2389
large number multiplication, only one set of data!
AC Code:

Import Java.math.biginteger;import Java.util.scanner;public class Main {public static void main (string[] args) {Scanner s c = new Scanner (system.in), while (Sc.hasnext ()) {BigInteger a = Sc.nextbiginteger (); BigInteger B = Sc.nextbiginteger (); System.out.println (a.multiply (b));}}}

AC Code 2:

#include <stdio.h> #include <string.h> #define MAX 220int Main () {char S1[max],s2[max];    int A1[max],a2[max],p[2*max];;    int i,j,len_1,len_2;    memset (a1,0,sizeof (A1));    Memset (a2,0,sizeof (A2));    memset (P,0,sizeof (p));    Gets (S1);    Gets (S2);    Len_1=strlen (S1);    Len_2=strlen (S2);    for (j=0,i=len_1-1;i>=0;i--) {a1[j++]=s1[i]-' 0 ';    } for (j=0,i=len_2-1;i>=0;i--) {a2[j++]=s2[i]-' 0 ';        } for (i=0;i<len_1;i++) {for (j=0;j<len_2;j++) {p[i+j]+=a1[i]*a2[j];            }} for (i=0;i<max*2;i++) {if (p[i]>9) {P[I+1]+=P[I]/10;        p[i]%=10;    }} int start=0;        for (i=max*2-1;i>=0;i--) {if (start) {printf ("%d", p[i]);            } else if (P[i]) {printf ("%d", p[i]);        Start=1;    }} if (!start) printf ("0"); return 0;}

POJ 2389 Bull Math (large number multiplication, or Java good)