#include<stdlib.h>
#include<iostream>
#define max 100 //最大位数
using namespace std;
void reverse(int *a,int i) //倒置
{
int m,n;
int temp;
n=i/2;
for(m=0;m<n;m++)
{
temp=*(a+m);
*(a+m)=*(a+i-m-1);
*(a+i-m-1)=temp;
}
}
void jinwei(int *a,int m) //进位
{
int i,j;
for(j=0;*(a+m+j)>=10;j++)
{
i=*(a+m+j)/10;
*(a+m+j)=*(a+m+j)%10;
*(a+m+j+1)=*(a+m+j+1)+i;
}
}
void *cal()
{
char *st1,*st2;
int *a,*b;
int *c;
int num[max]={0};
int i,j;
int k,m;
int out;
c=&num[0];
cout<<“input first number size:”;
cin>>i;
st1=new char(i);
cout<<“input first number:”;
cin>>st1;
cout<<“input second number size:”;
cin>>j;
st2=new char(j);
cout<<“input second number:”;
cin>>st2;
a=new int(i);
b=new int(j);
for(k=0;k<i;k++)
{
a[k]=st1[k]-48;
}
for(k=0;k<j;k++)
{
b[k]=st2[k]-48;
}
delete st1;
delete st2;
reverse(a,i);
reverse(b,j);
for(k=0;k<i;k++)
for(m=0;m<j;m++)
{
out=a[k]*b[m];
if(out<10)
{
c[k+m]=c[k+m]+out;
if(c[k+m]>=10)
{
jinwei(c,(k+m));
}
}
else
{
c[k+m]=c[k+m]+out;
jinwei(c,(k+m));
}
}
j=0;
for(i=max;i>=0;i–)
{
if(c[i]==0&&j==0)
continue;
if(c[i]!=0||j!=0)
{
cout<<c[i];
j=1;
}
}
cout<<endl;
}
int main()
{
cal();
system(“pause”);
return 0;
}
