```
#include <iostream>
#include <cstring>
using namespace std;
int c[10000],d[10000];
char a[10000],b[10000];
int temp[10000],wancheng[10000];
int main()
{
int i,j,head=0,lenc,tail=0,flag=1;
cin>>a>>b;
if(a[0]=='0'||b[0]=='0')
{
cout<<0<<endl;
return 0;
}
for(i=strlen(a)-1;i>=0;i--)
{
if(a[i]!='-')
c[head++]=a[i]-'0';
}
head=0;
for(i=strlen(b)-1;i>=0;i--)
{
if(b[i]!='-')
d[head++]=b[i]-'0';
}
if(a[0]=='-')
{
if(b[0]!='-')
cout<<'-';
}
if(a[0]!='-')
{
if(b[0]=='-')
cout<<'-';
}
for(i=0;i<max(strlen(a),strlen(b));i++)
{
for(j=0;j<min(strlen(a),strlen(b));j++)
{
temp[i+j]+=c[i]*d[j];
}
}
for(i=0;i<=max(strlen(a),strlen(b))*2;i++)
{
if(temp[i]>9)
{
wancheng[tail++]=temp[i]%10;
temp[i]/=10;
while(temp[i])
{
temp[i+1]+=temp[i]%10;
temp[i]/=10;
}
}
else
{
wancheng[tail++]=temp[i]%10;
}
}
for(i=max(strlen(a),strlen(b))*2;i>=0;i--)
if(wancheng[i]==0&&flag==1)
continue;
else
{
flag=0;
cout<<wancheng[i];
}
return 0;
}
```
by CiderLee @ 2018-02-07 20:58:08