[模板]高精度四则运算

struct Number{
	int a[N],n;bool POrN; 
	void init(){
		memset(a,0,sizeof(a));
		n=1;POrN=true;
	}
	void read(){
		init();--n;
		char c=getchar();
		while(!isdigit(c)){
			if(c=='-') POrN=false;
			c=getchar();
		}
		while(isdigit(c)){
			a[n++]=c-'0';c=getchar();
		}
	}
	void write(){
		if(!POrN) cout<<"-";
		for(int i=0;i<n;++i) cout<<a[i];
	}
	Number abs(const Number a){
		Number c=a;
		c.POrN=true;return c;
	}
	friend bool operator < (const Number a,const Number b){
		if(a.POrN^b.POrN) return !a.POrN;
		if(a.n^b.n) return a.n<b.n;
		for(int i=0;i<a.n;++i)
			if(a.a[i]^b.a[i]) return a.a[i]<b.a[i]; 
		return false;
	}
	friend bool operator <= (const Number a,const Number b){
		if(a.POrN^b.POrN) return !a.POrN;
		if(a.n^b.n) return a.n<b.n;
		for(int i=0;i<a.n;++i)
			if(a.a[i]^b.a[i]) return a.a[i]<=b.a[i]; 
		return false;
	}
	friend bool operator > (const Number a,const Number b){
		return b<a;
	}
	friend bool operator >= (const Number a,const Number b){
		return b<=a;
	}
	void tran(){
		for(int i=0;i<(n>>1);++i){
			swap(a[i],a[n-i-1]);
		}
	}
	Number add(Number a,Number b){
		Number c;c.init();
		c.n=max(a.n,b.n);
		a.tran();b.tran();
		for(int i=0;i<c.n;++i){
			c.a[i]+=a.a[i]+b.a[i];
			if(c.a[i]>=10){
				c.a[i]-=10;++c.a[i+1];
			}
		}
		while(c.a[c.n]) ++c.n;
		c.tran();
		return c;
	}
	Number sub(Number a,Number b){
		Number c;c.init();
		c.n=max(a.n,b.n);
		a.tran();b.tran();
		for(int i=0;i<c.n;++i){
			c.a[i]+=a.a[i]-b.a[i];
			if(c.a[i]<0) c.a[i]+=10,--c.a[i+1];
		}
		while(c.n>1&&!c.a[c.n-1]) --c.n;
		c.tran();
		return c;	
	}
	friend Number operator + (Number a,Number b){
		Number c;bool fl=false;
		if(a.POrN^b.POrN){
			if(!a.POrN){
				swap(a,b);fl=true;
			}
			if(a.abs(a)<b.abs(b)){
				c=c.sub(b,a);c.POrN=false;
			}
			else{
				c=c.sub(a,b);c.POrN=true;
			}
		}
		else{
			c=c.add(a,b);c.POrN=a.POrN;
		}
		if(fl) swap(a,b);
		return c;
	}
	friend Number operator - (const Number a,const Number b){
		Number c=b;c.POrN=!c.POrN;return a+c; 
	}
	friend Number operator * (Number a,Number b){
		Number c;c.init();
		c.n=a.n+b.n;
		c.POrN=!(a.POrN^b.POrN);
		a.tran();b.tran();
		for(int i=0;i<a.n;++i)
			for(int j=0;j<b.n;++j)
				c.a[i+j]+=a.a[i]*b.a[j];
		for(int i=0;i<c.n;++i)
			if(c.a[i]>10){
				c.a[i+1]+=c.a[i]/10;c.a[i]%=10;
			}
		while(c.n>1&&!c.a[c.n-1]) --c.n;
		a.tran();b.tran();c.tran();
		return c;
	}
	bool cmp(Number c,int s,int t){
		if(t-s>n) return true;
		if(t-s<n) return false;
		for(int i=0;i<n;++i){
			if(a[i]==c.a[s+i]) continue;
			return c.a[s+i]>a[i]; 
		}
		return true;
	}
	void sub(Number b,int s,int t){
		for(int i=t-1,j=b.n-1;j>=0;--i,--j){
			a[i]-=b.a[j];
			if(a[i]<0) a[i]+=10,--a[i-1];
		}
		return;
	}
	friend Number operator / (Number a,Number b){
		Number c,d=a;c.init();
		c.POrN=!(a.POrN^b.POrN);c.n=0;
		for(int s=0,t=b.n;t<=d.n;){
			while(b.cmp(d,s,t)){
				d.sub(b,s,t);++c.a[c.n];
				if(!d.a[s]) ++s;
			}
			++c.n;++t;
			if(!d.a[s]) ++s;
		}
		int cnt=0;
		while(cnt<c.n&&!c.a[cnt]) ++cnt;
		c.n-=cnt;
		for(int i=0;i<c.n;++i)
			c.a[i]=c.a[i+cnt];
		if(!c.n){
			++c.n;c.POrN=true;
		}
		return c;
	}
};

2020-01-01 10:53:51