高精度模板.

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

const int maxn = 1000;

struct bign{
    int d[maxn], len;

    void clean() { while(len > 1 && !d[len-1]) len--; }

    bign()             { memset(d, 0, sizeof(d)); len = 1; }
    bign(int num)     { *this = num; } 
    bign(char* num) { *this = num; }
    bign operator = (const char* num){
        memset(d, 0, sizeof(d)); len = strlen(num);
        for(int i = 0; i < len; i++) d[i] = num[len-1-i] - '0';
        clean();
        return *this;
    }
    bign operator = (int num){
        char s[20]; sprintf(s, "%d", num);
        *this = s;
        return *this;
    }

    bign operator + (const bign& b){
        bign c = *this; int i;
        for (i = 0; i < b.len; i++){
            c.d[i] += b.d[i];
            if (c.d[i] > 9) c.d[i]%=10, c.d[i+1]++;
        }
        while (c.d[i] > 9) c.d[i++]%=10, c.d[i]++;
        c.len = max(len, b.len);
        if (c.d[i] && c.len <= i) c.len = i+1;
        return c;
    }
    bign operator - (const bign& b){
        bign c = *this; int i;
        for (i = 0; i < b.len; i++){
            c.d[i] -= b.d[i];
            if (c.d[i] < 0) c.d[i]+=10, c.d[i+1]--;
        }
        while (c.d[i] < 0) c.d[i++]+=10, c.d[i]--;
        c.clean();
        return c;
    }
    bign operator * (const bign& b)const{
        int i, j; bign c; c.len = len + b.len; 
        for(j = 0; j < b.len; j++) 
                  for(i = 0; i < len; i++) 
                   c.d[i+j] += d[i] * b.d[j];
        for(i = 0; i < c.len-1; i++)
            c.d[i+1] += c.d[i]/10, c.d[i] %= 10;
        c.clean();
        return c;
    }
    bign operator / (const bign& b){
        int i, j;
        bign c = *this, a = 0;
        for (i = len - 1; i >= 0; i--)
        {
            a = a*10 + d[i];
            for (j = 0; j < 10; j++) if (a < b*(j+1)) break;
            c.d[i] = j;
            a = a - b*j;
        }
        c.clean();
        return c;
    }
    bign operator % (const bign& b){
        int i, j;
        bign a = 0;
        for (i = len - 1; i >= 0; i--)
        {
            a = a*10 + d[i];
            for (j = 0; j < 10; j++) if (a < b*(j+1)) break;
            a = a - b*j;
        }
        return a;
    }
    bign operator += (const bign& b){
        *this = *this + b;
        return *this;
    }

    bool operator <(const bign& b) const{
        if(len != b.len) return len < b.len;
        for(int i = len-1; i >= 0; i--)
            if(d[i] != b.d[i]) return d[i] < b.d[i];
        return false;
    }
    bool operator >(const bign& b) const{return b < *this;}
    bool operator<=(const bign& b) const{return !(b < *this);}
    bool operator>=(const bign& b) const{return !(*this < b);}
    bool operator!=(const bign& b) const{return b < *this || *this < b;}
    bool operator==(const bign& b) const{return !(b < *this) && !(b > *this);}

    string str() const{
        char s[maxn]={};
        for(int i = 0; i < len; i++) s[len-1-i] = d[i]+'0';
        return s;
    }
};

istream& operator >> (istream& in, bign& x)
{
    string s;
    in >> s;
    x = s.c_str();
    return in;
}

ostream& operator << (ostream& out, const bign& x)
{
    out << x.str();
    return out;
}
int main()
{
    freopen("noip.in","r",stdin);
    freopen("noip.out","w",stdout); 
    bign s=0,t;
    while (cin>>t)
    {
        if (t.len==1&&!t.d[0]) break;
        s=s+t;
    }
    cout<<s<<endl;
    return 0;
}

 写了个没有/和后面运算的简单一点的。。都是自己可以理解语法

/也挺简单 但感觉noip用不到

#include <bits/stdc++.h>
using namespace std;
const int maxn=1000;
#define IL inline
struct bign{
    int d[maxn],len;
    IL void clear() {while (len>1&&!d[len-1]) len--;}
    bign() {len=1;}
    bign(int num)     { *this = num; } 
    bign(char* num) { *this = num; }
    bign operator = (const char *num)
    {
        len=strlen(num);
        for (int i=0;i<len;i++) d[i]=num[len-i-1]-'0';
        clear();
        return *this;
    }
    bign operator =(int num)
    {
        char s[20];
        sprintf(s,"%d",num);
        *this=s;
        return *this;
    }
    bign operator + (const bign b)
    {
        bign c=*this;
        int i;
        for (i=0;i<b.len;i++)
          c.d[i]+=b.d[i],c.d[i+1]+=c.d[i]/10,c.d[i]%=10;
        c.len=max(c.len,b.len);
        if (c.d[c.len]) c.len++;
        return c;  
    }
    bign operator -(const bign b)
    {
        bign c=*this;
        int i;
        for (i=0;i<b.len;i++)
        {
          c.d[i]-=b.d[i];
          if (c.d[i]<0) c.d[i]+=10,c.d[i+1]--;
        }
        while (c.d[i]<0) c.d[i]+=10,c.d[i+1]--,i++;
        return c;
    }
    bign operator *(const bign b)
    {
        int i,j; bign c; c.len=b.len+len;
        for (j=0;j<b.len;j++)
          for (i=0;i<len;i++)
            c.d[i+j]+=b.d[j]*d[i];
        for (i=0;i<c.len;i++)
          c.d[i+1]+=c.d[i]/10,c.d[i]%=10;
        c.clear();
        return c;
    }
    string str()
    {
        char s[maxn]={};
        for (int i=0;i<len;i++) s[len-i-1]=d[i]+'0';
        return s;
    }
};
int main()
{
    bign a=3424,b=213123,c=324,d=123,e=1344,f=132;
    bign ans=(a+b)*(c+d)*(e-f);
    cout<<ans.str();
    return 0;
}