#include<string.h>
#include<iostream>
struct bign
{
int d[1000];
int len;
bign()
{
memset(d, 0, sizeof(d));
len = 0;
}
bign change(char str[])
{
bign a;
a.len = strlen(str);
for (int i = 0; i < a.len; i++)
{
a.d[i] = str[a.len - i - 1] - '0';
}
return a;
}
int compare(bign a, bign b)
{
if (a.len > b.len)
{
return 1;
}
else if (b.len > a.len)
{
return -1;
}
else
{
for (int i = a.len-1; i >=0; i--)
{
if (b.d[i] > a.d[i])
{
return -1;
}
if (a.d[i] > b.d[i])
{
return 1;
}
}
return 0;
}
}
bign add(bign a, bign b)//高精度a+b
{
bign c;
int carry = 0;//进位
for (int i = 0; i < a.len || i < b.len; i++)
{
int temp = a.d[i] + b.d[i] + carry;
c.d[c.len++] = temp % 10;
carry = temp / 10;
}
if (carry > 0)
{
c.d[c.len++] = carry;
}
return c;
}
void print(bign a)
{
for (int i = a.len - 1; i >= 0; i--)
{
printf("%d", a.d[i]);
}
}
bign sub(bign a, bign b)//高精度a-b
{
bign c;
for (int i = 0; i < a.len || i < b.len; i++)
{
if (a.d[i] < b.d[i])
{
a.d[i] += 10;
a.d[i + 1] --;
}
c.d[c.len++] = a.d[i]-b.d[i];
}
//去除高位的0
while (c.len - 1 > 0 && c.d[c.len - 1] == 0)
{
c.len--;
}
return c;
}
bign mul(bign a, int b)//高精度*低精度
{
bign c;
//将b看作一个整体
int carry = 0;
for (int i = 0; i < a.len; i++)
{
int temp = a.d[i] * b+carry;
carry = temp / 10;
c.d[c.len++] = temp % 10;
}
while (carry != 0)
{
c.d[c.len++] = carry % 10;
carry /= 10;
}
return c;
}
bign divide(bign a, int b, int& r)//高精度除法,r为余数
{
bign c;
c.len = a.len;
for (int i = a.len - 1; i >= 0; i--)
{
r = r * 10 + a.d[i];
if (r < b) {//不够除
c.d[i] = 0;
}
else {
c.d[i] = r / b;
r = r % b;
}
}
while (c.len - 1 > 0 && c.d[c.len - 1] == 0)
{
c.len--;
}
return c;
}
};