uva10590 整数拆分-大整数加法

#include<iostream>
#include<vector>
#include<cstring>
#include<cstdio>
#include<queue>
#include<string>
using namespace std;

class bign
{
public:
    int a[10];
    int leng;
    void print();
    bign () {leng=0;memset(a,0,sizeof(a));}
    bign operator +(bign &b) const;
};

void bign::print()                      
{
    int f=1;
    if(leng==0) printf("0");
    else
    for(int i=leng-1;i>=0;i--)
        {
            if(f) printf("%d",a[i]);
            else printf("%.9d",a[i]);
            f=0;
        }
}

bign bign::operator +(bign &b) const
{
    int top=leng>b.leng?leng:b.leng;
    bign c;
    for(int i=0,g=0;i<top+1;i++)
    {
        long long s=a[i]+b.a[i]+g;
        g=0;
        if(s<1000000000) c.a[i]=s;
        else {c.a[i]=s%1000000000;g=s/1000000000;}
    }
    int j;
    for(j=top+2;;j--)
        if(c.a[j]!=0) break;
    c.leng=j+1;
    return c;
}

bign dp[5010];
int main()
{
    int n;
    dp[0].a[0]=1;
    dp[0].leng=1;
    for(int i=1;i<=5000;i++)
    {
        for(int j=i;j<=5000;j++)
        {
            dp[j]=dp[j]+dp[j-i];
        }
    }

    while(scanf("%d",&n)!=EOF)
    {
        dp[n].print();
        putchar(10);
    }

    return 0;
}