Code
struct BigInteger
{
int len, negative;
int val[1005];
/* 转换 */
BigInteger(int x = 0)
{
I_TO_B(x);
}
BigInteger(char *st)
{
C_TO_B(st);
}
void C_TO_B(char *st)
{
negative = 0;
len = strlen(st);
memset(val, 0, sizeof(val));
rep(i, 0, len - 1) val[i] = st[len - i - 1] - '0';
if (st[0] == '-') val[--len] = 0, negative = 1;
while(len > 0 && val[len - 1] == 0) len--;
}
void I_TO_B(int x)
{
negative = 0;
if (x < 0) x = -x, negative = 1;
len = 0;
memset(val, 0, sizeof(val));
while(x)
{
val[len++] = x % 10;
x /= 10;
}
}
/* 输入输出 */
friend istream &operator >>(istream &in, BigInteger &t)
{
char st[1005];
in >> st;
t.C_TO_B(st);
return in;
}
friend ostream &operator <<(ostream &out, BigInteger &t)
{
if (t.negative) putchar('-');
per(i, t.len - 1, 0)
out << t.val[i];
return out;
}
void print()
{
if (negative) putchar('-');
per(i, len - 1, 0)
putchar(val[i] + '0');
putchar('
');
}
/* 其他 */
friend void swap(BigInteger &x, BigInteger &y)
{
BigInteger t = x;
x = y;
y = t;
}
friend BigInteger operator -(BigInteger x)
{
BigInteger t = x;
t.negative = 1 - t.negative;
return t;
}
friend BigInteger abs(BigInteger x)
{
BigInteger t = x;
t.negative = 0;
return t;
}
/* 等于 or 不等于 */
friend bool operator ==(BigInteger x, BigInteger y)
{
if (x.negative != y.negative) return 0;
if (x.len != y.len) return 0;
per(i, x.len - 1, 0)
if (x.val[i] != y.val[i]) return 0;
return 1;
}
friend bool operator ==(BigInteger x, int t)
{
BigInteger y;
y.I_TO_B(t);
return x == y;
}
friend bool operator ==(int t, BigInteger y)
{
BigInteger x;
x.I_TO_B(t);
return x == y;
}
friend bool operator !=(BigInteger x, BigInteger y)
{
return !(x == y);
}
friend bool operator !=(BigInteger x, int t)
{
BigInteger y;
y.I_TO_B(t);
return !(x == y);
}
friend bool operator !=(const int t, const BigInteger y)
{
BigInteger x;
x.I_TO_B(t);
return !(x == y);
}
/* 小于 or 大于 */
friend bool operator <(BigInteger x, BigInteger y)
{
if (x.negative && !y.negative) return 1;
if (!x.negative && y.negative) return 0;
if (x.negative && y.negative) swap(x, y);
if (x.len < y.len) return 1;
if (x.len > y.len) return 0;
per(i, x.len - 1, 0)
if (x.val[i] < y.val[i]) return 1;
else if (x.val[i] > y.val[i]) return 0;
return 0;
}
friend bool operator <(BigInteger x, int t)
{
BigInteger y;
y.I_TO_B(t);
return x < y;
}
friend bool operator <(int t, BigInteger y)
{
BigInteger x;
x.I_TO_B(t);
return x < y;
}
friend bool operator >(BigInteger x, BigInteger y)
{
return y < x;
}
friend bool operator >(BigInteger x, int y)
{
return y < x;
}
friend bool operator >(int x, BigInteger y)
{
return y < x;
}
/* 小于等于 or 大于等于 */
friend bool operator <=(BigInteger x, BigInteger y)
{
return x < y || x == y;
}
friend bool operator <=(BigInteger x, int t)
{
BigInteger y;
y.I_TO_B(t);
return x < y || x == y;
}
friend bool operator <=(int t, BigInteger y)
{
BigInteger x;
x.I_TO_B(t);
return x < y || x == y;
}
friend bool operator >=(BigInteger x, BigInteger y)
{
return y <= x;
}
friend bool operator >=(BigInteger x, int y)
{
return y <= x;
}
friend bool operator >=(int x, BigInteger y)
{
return y <= x;
}
/* 加法 */
friend BigInteger operator +(BigInteger x, BigInteger y)
{
if (x.negative && y.negative) return -(abs(x) + abs(y));
if (x.negative && !y.negative) return y - abs(x);
if (!x.negative && y.negative) return x - abs(y);
int len = x.len > y.len ? x.len : y.len;
BigInteger ans;
rep(i, 0, len - 1)
{
ans.val[i] += x.val[i] + y.val[i];
ans.val[i + 1] += ans.val[i] / 10;
ans.val[i] %= 10;
}
if (ans.val[len] != 0) len++;
ans.len = len;
return ans;
}
friend BigInteger operator +(BigInteger x, int t)
{
BigInteger y;
y.I_TO_B(t);
return x + y;
}
friend void operator +=(BigInteger &x, BigInteger y)
{
x = x + y;
}
friend void operator +=(BigInteger &x, int t)
{
x = x + t;
}
friend void operator ++(BigInteger &x)
{
x += 1;
}
/* 减法 */
friend BigInteger operator -(BigInteger x, BigInteger y)
{
if (x.negative && y.negative) return abs(y) - abs(x);
if (x.negative && !y.negative) return -(abs(x) + y);
if (!x.negative && y.negative) return x + abs(y);
BigInteger ans;
if (x < y)
{
swap(x, y);
ans.negative = 1;
}
int len = max(x.len, y.len);
rep(i, 0, len - 1)
{
ans.val[i] += x.val[i] - y.val[i];
if (ans.val[i] < 0)
{
ans.val[i] += 10;
ans.val[i + 1]--;
}
}
while(len > 1 && ans.val[len - 1] == 0) len--;
ans.len = len;
return ans;
}
friend BigInteger operator -(int t, BigInteger y)
{
BigInteger x;
x.I_TO_B(t);
return x - y;
}
friend BigInteger operator -(BigInteger x, int t)
{
BigInteger y;
y.I_TO_B(t);
return x - y;
}
friend void operator -=(BigInteger &x, BigInteger y)
{
x = x - y;
}
friend void operator -=(BigInteger &x, int y)
{
x = x - y;
}
friend void operator --(BigInteger &x)
{
x -= 1;
}
/* 乘法 */
friend BigInteger operator *(BigInteger x, BigInteger y)
{
BigInteger ans;
ans.negative = (x.negative ^ y.negative);
int len = x.len + y.len;
rep(i, 0, x.len - 1)
rep(j, 0, y.len - 1)
ans.val[i + j] += x.val[i] * y.val[j];
rep(i, 0, len - 1)
{
ans.val[i + 1] += ans.val[i] / 10;
ans.val[i] %= 10;
}
while(len > 1 && ans.val[len - 1] == 0) len--;
ans.len = len;
return ans;
}
friend BigInteger operator *(BigInteger x, int t)
{
BigInteger y;
y.I_TO_B(t);
return x * y;
}
friend BigInteger operator *(int t, BigInteger y)
{
BigInteger x;
x.I_TO_B(t);
return x * y;
}
friend void operator *=(BigInteger &x, BigInteger y)
{
x = x * y;
}
friend void operator *=(BigInteger &x, int t)
{
x = x * t;
}
/* 除法 */
friend BigInteger operator /(BigInteger x, BigInteger y)
{
BigInteger R, ans;
if (y.len == 1 && y.val[0] == 0) return R;
per(i, x.len - 1, 0)
{
ans *= 10;
R = R * 10 + x.val[i];
while(R >= y)
{
++ans;
R -= y;
}
}
return ans;
}
friend BigInteger operator /(BigInteger x, int t)
{
BigInteger y;
y.I_TO_B(t);
return x / y;
}
friend BigInteger operator %(BigInteger x, BigInteger y)
{
return x - x / y;
}
friend BigInteger operator %(BigInteger x, int t)
{
return x - x / t;
}
friend void operator /=(BigInteger &x, BigInteger y)
{
x = x / y;
}
friend void operator /=(BigInteger &x, int t)
{
x = x / t;
}
friend void operator %=(BigInteger &x, BigInteger y)
{
x = x % y;
}
friend void operator %=(BigInteger &x, int t)
{
x = x % t;
}
};