HDU1002 A + B Problem II

/*
 HDU1002 A + B Problem II
 http://acm.hdu.edu.cn/showproblem.php?pid=1002
 高精度加法
 *
 */
#include <cstring>
#include <cstdio>
#include <algorithm>
using namespace std;
const int Nmax=1000;
struct BigInt
{
    int a[Nmax];
    int n;
    void init() 
    {
        for(int i=0;i<Nmax;i++)
            a[i]=0;
    }
    BigInt()
    {
        init();
        n=0;
    }
    BigInt(int _a[],int _n)
    {
        init();
        n=_n;
        //for(int i=0;i<Nmax;i++)
            //a[i]=0;
        for(int i=1;i<=n;i++)
            a[i]=_a[i];
        maintain();
    }
    BigInt(char s[])
    {
        init();
        n=strlen(s+1);
        for(int i=1;i<=n;i++)
            a[i]=s[n-i+1]-'0';
        maintain();
    }
    BigInt(long long  x)
    {
        init();
        n=0;
        while(x>0LL)
        {
            a[++n]=x%10LL;
            x/=10LL;
        }
    }
    BigInt(int x)
    {
        init();
        n=0;
        while(x>0)
        {
            a[++n]=x%10;
            x/=10;
        }
    }
    void read()
    {
        init();
        n=0;
        char c=getchar();
        if(c==-1)
            return;
        while(c==' ' || c=='
' )
        {
            c=getchar();
            if(c==-1)
                break;
        }
        int num[Nmax];
        while(c!=' ' && c!='
' && c!=-1)
        {
            num[++n]=c-'0';
            c=getchar();
        }
        for(int i=1;i<=n;i++)
            a[i]=num[n-i+1];
        maintain();
    }
    void print()
    {
        if(n==0)
            printf("0");
        for(int i=n;i>=1;i--)
            printf("%d",a[i]);
    }
    void maintain()
    {
        for(int i=1;i<=n;i++)
        {
            a[i+1]+=a[i]/10;
            a[i]%=10;
        }
        int j=n+1;
        while(a[j]!=0)
        {
            a[j+1]+=a[j]/10;
            a[j]%=10;
            j++;
        }
        n=j-1;
        while(a[n]==0 && n>1)
            n--;
    }
    friend BigInt operator + (BigInt a,BigInt b)
    {
        int len=max(a.n,b.n);
        BigInt ans;
        ans.n=len;
        for(int i=1;i<=len;i++)
            ans.a[i]=a.a[i]+b.a[i];
        ans.maintain();
        return ans;
    }
    //friend BigInt operator - (BigInt a,BigInt b)
    //{
        //int len=max(a.n,b.n);
        //BigInt ans;
        //ans.n=len;
        //for(int i=1;i<=len;i++)
            //ans.a[i]=a.a[i]-b.a[i];
        //for(int i=1;i<=len;i++)
        //{
            //if(ans.a[i]<0)
            //{
                //ans.a[i]+=10;
                //a.a[i+1]--;
            //}
                //ans.a[i]+=10
        //}
    //}
    friend BigInt operator * (BigInt b,int a)
    {
        int n=b.n;
        BigInt ans;
        ans.n=n;
        for(int i=1;i<=n;i++)
            ans.a[i]=b.a[i]*a;
        ans.maintain();
        return ans;
    }
    friend BigInt operator * (int a,BigInt b)
    {
        int n=b.n;
        BigInt ans;
        ans.n=n;
        for(int i=1;i<=n;i++)
            ans.a[i]=b.a[i]*a;
        ans.maintain();
        return ans;
    }
    friend BigInt operator * (BigInt a,BigInt b)
    {
        BigInt ans;
        ans.n=a.n+b.n-1;
        for(int i=1;i<=a.n;i++)
            for(int j=1;j<=b.n;j++)
                ans.a[j+i-1]=a.a[i]*b.a[j];   
        ans.maintain();
        return ans;
    }
};
int main()
{
    char s[1002];
    char s1[1002];
    BigInt a,b;
    //freopen("test.in","r",stdin);
    int t;
    scanf("%d",&t);
    for(int ttt=1;ttt<=t;ttt++)
    {
        printf("Case %d:
",ttt);
        a.read();
        b.read();
        a.print();
        printf(" + ");
        b.print();
        printf(" = ");
        (a+b).print();
        printf("
");
        if(ttt!=t)
            printf("
");
        //scanf("%lld",&n);
        //a.print();
    }
    return 0;
}