高精度模板

struct BigNum {
    int val[N], len = 1;
    void init() { val[1] = len = 1; }
    BigNum operator + (const BigNum &x) const {
        static BigNum t = *this;
        t.len = max(t.len, x.len);
        for (int i = 1; i <= t.len; i++) t.val[i] += x.val[i];
        for (int i = 1; i <= len; i++) t.val[i + 1] += t.val[i] / 10, t.val[i] %= 10;
        while (t.val[len] > 9) t.val[len + 1] += t.val[len] / 10, t.val[len] %= 10, t.len++;
        return t;
    }
    BigNum operator - (const BigNum &x) const {
        static BigNum t = *this;
        t.len = max(t.len, x.len);
        for (int i = 1; i <= max(t.len, x.len); i++) t.val[i] -= x.val[i];
        for (int i = 1; i <= len; i++) 
            if (t.val[i] < 0) 
                t.val[i] += (9 - t.val[i]) / 10 * 10, t.val[i + 1] -= (9 - t.val[i]) / 10 * 10;
        while (t.len > 1 && t.val[len] == 0) t.len--;
        return t;
    }
    BigNum operator * (const BigNum &x) const {
        static BigNum t = *this;
        for (int i = 1; i <= t.len; i++) 
            for (int j = 1; j <= x.len; j++) 
                t.val[i + j - 1] += val[i] * x.val[j];
        for (int i = 1; i <= t.len + x.len; i++) t.val[i + 1] += t.val[i] / 10, t.val[i] %= 10;
        t.len += x.len;
        while (t.len > 1 && t.val[len] == 0) t.len--;
        return t;
    }
    BigNum operator / (int x) const{
        static BigNum t;
        int s = 0;
        for (int i = t.len - 1; i >= 0; i--) {
            s = s * 10 + t.val[i];
            t.val[i] = s / x;
            s %= x;
        }
        while (t.len > 0 && val[t.len - 1] == 0) t.len--;
        return t;
    }
    int cmp(const BigNum &x) const {
        if (len != x.len) return len < x.len;
        for (int i = len; i >= 1; i--) if (val[i] != x.val[i]) return val[i] < x.val[i];
        return 2;
    }
    bool operator < (const BigNum &x) const {
        return !cmp(x);
    }
    bool operator = (const BigNum &x) const {
        return cmp(x) == 2;
    }
    bool operator > (const BigNum &x) const {
        return cmp(x);
    }
    void print() const{
        for (int i = len; i >= 1; i--) printf("%d", val[i]);
        puts("");
    }
};