UVA - 10106 Product

UVA - 10106 Product

/*************************************************************************
> File Name: UVA-10106.cpp
> Author: Robin
> Mail: 499549060@qq.com
> Created Time: 2016年07月19日 星期二 14时46分37秒
************************************************************************/

#include<iostream>
#include<cstdio>
#include<cmath>
#include<algorithm>
#include<cstring>
using namespace std;
int main() {
char x1[100000],x2[100000];
int a1[100000];
int a2[100000];
int a3[100000];
while (scanf("%s%s", x1, x2) != EOF) {
memset(a1, 0, sizeof(a1));
memset(a2, 0, sizeof(a2));
memset(a3, 0, sizeof(a3));
int len1 = strlen(x1);
int len2 = strlen(x2);
int jj = 0;
for (int i = len1 - 1; i >= 0; i--, jj++)
a1[jj] = x1[i] - '0';
jj = 0;
for (int i = len2 - 1; i >= 0; i--, jj++)
a2[jj] = x2[i] - '0';
for (int i = 0; i < len1; i++) {
int s = 0;
for (int j = 0; j < len2; j++) {
s = a3[i+j]+a1[i]*a2[j];
a3[j+i] = s%10;
a3[i+j+1] += s/10;
}
}
int f;
if (a3[len1 + len2 - 1] > 0) {
f =  len1 + len2 - 1;
}
else
f = len1 + len2 - 2;
for (int i = f; i >= 0; i--) {
printf("%d", a3[i]);
if (a3[i] == 0 && i == f)
break;
}
printf("\n");

}
}