看到一个非常不错的高精度模板，记录一下

#include<cstdio>
#include<cstring>
using namespace std;
typedef long long ll;
const int base = 1e8;
const int N = 1e4 + 10;
int aux[N << 3];
struct bigint {
	int s[N], l;
	void CL() { l = 0; memset(s, 0, sizeof(s)); }
	void pr()
	{
		printf("%d", s[l]);
		for (int i = l - 1; i; i--)
			printf("%08d", s[i]);
	}
	void re_l()
	{
		int i, x = 0, k = 1, L = 0, fl, o;
		char c = getchar();
		for (; c < '0' || c > '9'; c = getchar());
		for (; c >= '0' && c <= '9'; c = getchar())
		{
			if (!(L - 1) && !aux[L])
				L--;
			aux[++L] = c - '0';
		}
		CL();
		l = L / 8 + ((o = L % 8) > 0);
		for (i = 1; i <= o; i++)
			x = x * 10 + aux[i];
		if (o)
			s[l] = x;
		for (fl = !o ? l + 1 : l, i = o + 1, x = 0; i <= L; i++, k++)
		{
			x = x * 10 + aux[i];
			if (!(k ^ 8))
				s[--fl] = x, x = k = 0;
		}
		if (!l)
			l = 1;
	}
	ll toint()
	{
		ll x = 0;
		for (int i = l; i; i--)
			x = x * base + s[i];
		return x;
	}
	bigint operator = (int b)
	{
		CL();
		do
		{
			s[++l] = b % base;
			b /= base;
		} while (b > 0);
		return *this;
	}
	bigint operator = (ll b)
	{
		CL();
		do
		{
			s[++l] = b % base;
			b /= base;
		} while (b > 0);
		return *this;
	}
	bigint operator + (const int& b)
	{
		bigint c = *this;
		ll x = b;
		for (int i = 1; i <= l && x; i++)
		{
			x = x + c.s[i];
			c.s[i] = x % base;
			x /= base;
		}
		if (x)
			c.s[++c.l] = x;
		return c;
	}
	bigint operator + (const ll & b)
	{
		bigint c = *this;
		ll x = b;
		for (int i = 1; i <= l && x; i++)
		{
			x = x + c.s[i];
			c.s[i] = x % base;
			x /= base;
		}
		if (x)
			c.s[++c.l] = x;
		return c;
	}
	bigint operator + (bigint & b)
	{
		if (b.l < 3)
			return *this + b.toint();
		bigint c;
		ll x = 0;
		int k = l < b.l ? b.l : l;
		c.CL(); c.l = k;
		for (int i = 1; i <= k; i++)
		{
			x = x + s[i] + b.s[i];
			c.s[i] = x % base;
			x /= base;
		}
		if (x)
			c.s[++c.l] = x;
		return c;
	}
	bigint operator - (const bigint & b)
	{
		bigint c, d = *this;
		ll x = 0;
		c.CL();
		for (int i = 1; i <= l; i++)
		{
			if ((x = d.s[i]) < b.s[i])
			{
				d.s[i + 1]--;
				x += base;
			}
			c.s[i] = x - b.s[i];
		}
		c.l = l;
		for (; !c.s[c.l] && c.l > 1; c.l--);
		return c;
	}
	bigint operator - (const int& b) { bigint c; return *this - (c = b); }
	bigint operator - (const ll & b) { bigint c; return *this - (c = b); }
	bigint operator * (const int& b)
	{
		bigint c;
		ll x = 0;
		c.CL();
		for (int i = 1; i <= l; i++)
		{
			x = x + 1LL * s[i] * b;
			c.s[i] = x % base;
			x /= base;
		}
		for (c.l = l; x; x /= base)
			c.s[++c.l] = x % base;
		return c;
	}
	bigint operator * (bigint & b)
	{
		if (b.l < 2)
			return *this * b.toint();
		bigint c;
		ll x;
		int i, j, k;
		c.CL();
		for (i = 1; i <= l; i++)
		{
			x = 0;
			for (j = 1; j <= b.l; j++)
			{
				x = x + 1LL * s[i] * b.s[j] + c.s[k = i + j - 1];
				c.s[k] = x % base;
				x /= base;
			}
			if (x)
				c.s[i + b.l] = x;
		}
		for (c.l = l + b.l; !c.s[c.l] && c.l > 1; c.l--);
		return c;
	}
	bigint operator * (const ll & b)
	{
		bigint c;
		if (b > 2e9)
		{
			c = b;
			return *this* c;
		}
		ll x = 0;
		c.CL();
		for (int i = 1; i <= l; i++)
		{
			x = x + b * s[i];
			c.s[i] = x % base;
			x /= base;
		}
		for (c.l = l; x; x /= base)
			c.s[++c.l] = x % base;
		return c;
	}
	bigint operator / (const int& b)
	{
		bigint c;
		ll x = 0;
		c.CL();
		for (int i = l; i; i--)
		{
			c.s[i] = (x * base + s[i]) / b;
			x = (x * base + s[i]) % b;
		}
		for (c.l = l; !c.s[c.l] && c.l > 1; c.l--);
		return c;
	}
	bigint operator / (const ll & b)
	{
		bigint c;
		ll x = 0;
		c.CL();
		for (int i = l; i; i--)
		{
			c.s[i] = (x * base + s[i]) / b;
			x = (x * base + s[i]) % b;
		}
		for (c.l = l; !c.s[c.l] && c.l > 1; c.l--);
		return c;
	}
	bigint operator / (bigint & b)
	{
		if (b.l < 2)
			return *this / b.toint();
		bigint c, d;
		int i, j, le, r, mid, k;
		c.CL(); d.CL();
		for (i = l; i; i--)
		{
			for (j = ++d.l; j > 1; j--)
				d.s[j] = d.s[j - 1];
			d.s[1] = s[i];
			if (d < b)
				continue;
			le = k = 0; r = base - 1;
			while (le <= r)
			{
				mid = (le + r) >> 1;
				b * mid <= d ? le = mid + 1, k = mid : r = mid - 1;
			}
			c.s[i] = k; d = d - b * k;
		}
		for (c.l = l; !c.s[c.l] && c.l > 1; c.l--);
		return c;
	}
	bigint operator % (const int& b)
	{
		bigint c;
		ll x = 0;
		c.CL();
		for (int i = l; i; i--)
			x = (x * base + s[i]) % b;
		return c = x;
	}
	bigint operator % (const ll & b)
	{
		bigint c;
		ll x = 0;
		c.CL();
		for (int i = l; i; i--)
			x = (x * base + s[i]) % b;
		return c = x;
	}
	bigint operator % (bigint & b)
	{
		if (b.l < 2)
			return *this % b.toint();
		bigint c;
		int i, j, le, r, mid, k;
		c.CL();
		for (i = l; i; i--)
		{
			for (j = ++c.l; j > 1; j--)
				c.s[j] = c.s[j - 1];
			c.s[1] = s[i];
			if (c < b)
				continue;
			le = k = 0; r = base - 1;
			while (le <= r)
			{
				mid = (le + r) >> 1;
				b * mid <= c ? le = mid + 1, k = mid : r = mid - 1;
			}
			c = c - b * k;
		}
		for (; !c.s[c.l] && c.l > 1; c.l--);
		return c;
	}
	bigint operator += (bigint & b) { return *this = *this + b; }
	bigint operator += (ll b) { return *this = *this + b; }
	bigint operator += (int b) { return *this = *this + b; }
	bigint operator -= (bigint & b) { return *this = *this - b; }
	bigint operator -= (ll b) { return *this = *this - b; }
	bigint operator -= (int b) { return *this = *this - b; }
	bigint operator *= (bigint & b) { return *this = *this * b; }
	bigint operator *= (ll b) { return *this = *this * b; }
	bigint operator *= (int b) { return *this = *this * b; }
	bigint operator /= (bigint & b) { return *this = *this / b; }
	bigint operator /= (ll b) { return *this = *this / b; }
	bigint operator /= (int b) { return *this = *this / b; }
	bigint operator %= (bigint & b) { return *this = *this % b; }
	bigint operator %= (ll b) { return *this = *this % b; }
	bigint operator %= (int b) { return *this = *this % b; }
	bool operator < (const bigint & b) const
	{
		if (l ^ b.l)
			return l < b.l;
		for (int i = l; i; i--)
			if (s[i] ^ b.s[i])
				return s[i] < b.s[i];
		return false;
	}
	bool operator <= (const bigint & b) const
	{
		if (l ^ b.l)
			return l < b.l;
		for (int i = l; i; i--)
			if (s[i] ^ b.s[i])
				return s[i] < b.s[i];
		return true;
	}
	bool operator > (const bigint & b) const
	{
		if (l ^ b.l)
			return l > b.l;
		for (int i = l; i; i--)
			if (s[i] ^ b.s[i])
				return s[i] > b.s[i];
		return false;
	}
	bool operator >= (const bigint & b) const
	{
		if (l ^ b.l)
			return l > b.l;
		for (int i = l; i; i--)
			if (s[i] ^ b.s[i])
				return s[i] > b.s[i];
		return true;
	}
	bool operator == (const bigint & b) const
	{
		if (l ^ b.l)
			return false;
		for (int i = l; i; i--)
			if (s[i] ^ b.s[i])
				return false;
		return true;
	}
	bool operator != (const bigint & b) const
	{
		if (l ^ b.l)
			return true;
		for (int i = l; i; i--)
			if (s[i] ^ b.s[i])
				return true;
		return false;
	}
	bool operator < (ll b) const { bigint c; return *this < (c = b); }
	bool operator <= (ll b) const { bigint c; return *this <= (c = b); }
	bool operator > (ll b) const { bigint c; return *this > (c = b); }
	bool operator >= (ll b) const { bigint c; return *this >= (c = b); }
	bool operator == (ll b) const { bigint c; return *this == (c = b); }
	bool operator != (ll b) const { bigint c; return *this != (c = b); }
	bool operator < (int b) const { bigint c; return *this < (c = b); }
	bool operator <= (int b) const { bigint c; return *this <= (c = b); }
	bool operator > (int b) const { bigint c; return *this > (c = b); }
	bool operator >= (int b) const { bigint c; return *this >= (c = b); }
	bool operator == (int b) const { bigint c; return *this == (c = b); }
	bool operator != (int b) const { bigint c; return *this != (c = b); }
};
bigint a, b;
int main()
{
	a.re_l(); b.re_l();
	(a + b).pr(); printf("\n");
	if (a < b)
		putchar('-'), (b - a).pr();
	else
		(a - b).pr();
	printf("\n");
	(a * b).pr(); printf("\n");
	(a / b).pr(); printf("\n");
	(a % b).pr(); printf("\n");
	if (a < b)
		printf("a < b\n");
	if (a <= b)
		printf("a <= b\n");
	if (a > b)
		printf("a > b\n");
	if (a >= b)
		printf("a >= b\n");
	if (a == b)
		printf("a == b\n");
	if (a != b)
		printf("a != b\n");
	return 0;
}