UVA10069 Distinct Subsequences 超级大数 + DP

一万多的代码，看着好乱，有点吓人，JAVA还没学会，不然就很短了

题意是给你一个母串一个子串，问你子串在母串中出现的次数，一个字母可以用多次，但是没找到一个 子串它的元素 下标组合必须不同

比如母串babgbag?

子串bag,

你可以找到 五个，

rabbbit
rabbit

你可以找到三个

总是做算法，不如来个陶冶情操的文章一篇：?http://www.sanwen.net/subject/3628849/

数的时候用的是排列组合的方法来数的，DP方程比较简单的，直接for两层找相同的，有点话就加上之前 保存的

dp[i][j] += dp[i-][j-1]

一开始找案例找了半天不是到哪里错，后来看到题目说 保证 答案不超过 10^100，那这个数就太大了 ，只能用大数来做

#include<iostream>
#include<cstdio>
#include<list>
#include<algorithm>
#include<cstring>
#include<string>
#include<queue>
#include<stack>
#include<map>
#include<vector>
#include<cmath>
#include<memory.h>
#include<set>

#define ll long long

#define eps 1e-8

#define inf 0xfffffff

//const ll INF = 1ll<<61;

using namespace std;

//vector<pair<int,int> > G;
//typedef pair<int,int > P;
//vector<pair<int,int> > ::iterator iter;
//
//map<ll,int >mp;
//map<ll,int >::iterator p;

const int N = 10000 + 5;
const int M = 100 + 5;


#define DIGIT	4
#define DEPTH	10000
#define MAX     101
typedef int bignum_t[MAX + 1];

int read(bignum_t a,istream& is = cin){
	char buf[MAX*DIGIT + 1],ch;
	int i,j;
	memset((void*)a,sizeof(bignum_t));
	if (!(is >> buf))	return 0;
	for (a[0] = strlen(buf),i = a[0] / 2 - 1; i >= 0; i--)
		ch = buf[i],buf[i] = buf[a[0] - 1 - i],buf[a[0] - 1 - i] = ch;
	for (a[0] = (a[0] + DIGIT - 1) / DIGIT,j = strlen(buf); j<a[0] * DIGIT; buf[j++] = '0');
	for (i = 1; i <= a[0]; i++)
		for (a[i] = 0,j = 0; j<DIGIT; j++)
			a[i] = a[i] * 10 + buf[i*DIGIT - 1 - j] - '0';
	for (; !a[a[0]] && a[0]>1; a[0]--);
	return 1;
}

void write(const bignum_t a,ostream& os = cout){
	int i,j;
	for (os << a[i = a[0]],i--; i; i--)
		for (j = DEPTH / 10; j; j /= 10)
			os << a[i] / j % 10;
}

int comp(const bignum_t a,const bignum_t b){
	int i;
	if (a[0] != b[0])
		return a[0] - b[0];
	for (i = a[0]; i; i--)
		if (a[i] != b[i])
			return a[i] - b[i];
	return 0;
}

int comp(const bignum_t a,const int b){
	int c[12] = { 1 };
	for (c[1] = b; c[c[0]] >= DEPTH; c[c[0] + 1] = c[c[0]] / DEPTH,c[c[0]] %= DEPTH,c[0]++);
	return comp(a,c);
}

int comp(const bignum_t a,const int c,const int d,const bignum_t b){
	int i,t = 0,O = -DEPTH * 2;
	if (b[0] - a[0]<d&&c)
		return 1;
	for (i = b[0]; i>d; i--){
		t = t*DEPTH + a[i - d] * c - b[i];
		if (t>0) return 1;
		if (t<O) return 0;
	}
	for (i = d; i; i--){
		t = t*DEPTH - b[i];
		if (t>0) return 1;
		if (t<O) return 0;
	}
	return t>0;
}

void add(bignum_t a,const bignum_t b){
	int i;
	for (i = 1; i <= b[0]; i++)
		if ((a[i] += b[i]) >= DEPTH)
			a[i] -= DEPTH,a[i + 1]++;
	if (b[0] >= a[0])
		a[0] = b[0];
	else
		for (; a[i] >= DEPTH&&i<a[0]; a[i] -= DEPTH,i++,a[i]++);
	a[0] += (a[a[0] + 1]>0);
}

void add(bignum_t a,const int b){
	int i = 1;
	for (a[1] += b; a[i] >= DEPTH&&i<a[0]; a[i + 1] += a[i] / DEPTH,a[i] %= DEPTH,i++);
	for (; a[a[0]] >= DEPTH; a[a[0] + 1] = a[a[0]] / DEPTH,a[a[0]] %= DEPTH,a[0]++);
}

void sub(bignum_t a,const bignum_t b){
	int i;
	for (i = 1; i <= b[0]; i++)
		if ((a[i] -= b[i])<0)
			a[i + 1]--,a[i] += DEPTH;
	for (; a[i]<0; a[i] += DEPTH,a[i]--);
	for (; !a[a[0]] && a[0]>1; a[0]--);
}

void sub(bignum_t a,const int b){
	int i = 1;
	for (a[1] -= b; a[i]<0; a[i + 1] += (a[i] - DEPTH + 1) / DEPTH,a[i] -= (a[i] - DEPTH + 1) / DEPTH*DEPTH,i++);
	for (; !a[a[0]] && a[0]>1; a[0]--);
}

void sub(bignum_t a,const bignum_t b,const int d){
	int i,O = b[0] + d;
	for (i = 1 + d; i <= O; i++)
		if ((a[i] -= b[i - d] * c)<0)
			a[i + 1] += (a[i] - DEPTH + 1) / DEPTH,a[i] -= (a[i] - DEPTH + 1) / DEPTH*DEPTH;
	for (; a[i]<0; a[i + 1] += (a[i] - DEPTH + 1) / DEPTH,i++);
	for (; !a[a[0]] && a[0]>1; a[0]--);
}

void mul(bignum_t c,const bignum_t a,j;
	memset((void*)c,sizeof(bignum_t));
	for (c[0] = a[0] + b[0] - 1,i = 1; i <= a[0]; i++)
		for (j = 1; j <= b[0]; j++)
			if ((c[i + j - 1] += a[i] * b[j]) >= DEPTH)
				c[i + j] += c[i + j - 1] / DEPTH,c[i + j - 1] %= DEPTH;
	for (c[0] += (c[c[0] + 1]>0); !c[c[0]] && c[0]>1; c[0]--);
}

void mul(bignum_t a,const int b){
	int i;
	for (a[1] *= b,i = 2; i <= a[0]; i++){
		a[i] *= b;
		if (a[i - 1] >= DEPTH)
			a[i] += a[i - 1] / DEPTH,a[i - 1] %= DEPTH;
	}
	for (; a[a[0]] >= DEPTH; a[a[0] + 1] = a[a[0]] / DEPTH,a[0]++);
	for (; !a[a[0]] && a[0]>1; a[0]--);
}

void mul(bignum_t b,const int d){
	int i;
	memset((void*)b,sizeof(bignum_t));
	for (b[0] = a[0] + d,i = d + 1; i <= b[0]; i++)
		if ((b[i] += a[i - d] * c) >= DEPTH)
			b[i + 1] += b[i] / DEPTH,b[i] %= DEPTH;
	for (; b[b[0] + 1]; b[0]++,b[b[0] + 1] = b[b[0]] / DEPTH,b[b[0]] %= DEPTH);
	for (; !b[b[0]] && b[0]>1; b[0]--);
}

void div(bignum_t c,bignum_t a,const bignum_t b){
	int h,l,m,i;
	memset((void*)c,sizeof(bignum_t));
	c[0] = (b[0]<a[0] + 1) ? (a[0] - b[0] + 2) : 1;
	for (i = c[0]; i; sub(a,b,c[i] = m,i - 1),i--)
		for (h = DEPTH - 1,l = 0,m = (h + l + 1) >> 1; h>l; m = (h + l + 1) >> 1)
			if (comp(b,i - 1,a)) h = m - 1;
			else l = m;
			for (; !c[c[0]] && c[0]>1; c[0]--);
			c[0] = c[0]>1 ? c[0] : 1;
}

void div(bignum_t a,const int b,int& c){
	int i;
	for (c = 0,i = a[0]; i; c = c*DEPTH + a[i],a[i] = c / b,c %= b,i--);
	for (; !a[a[0]] && a[0]>1; a[0]--);
}

void sqrt(bignum_t b,bignum_t a){
	int h,i;
	memset((void*)b,sizeof(bignum_t));
	for (i = b[0] = (a[0] + 1) >> 1; i; sub(a,b[i] += m,b[i] = m = (h + l + 1) >> 1; h>l; b[i] = m = (h + l + 1) >> 1)
			if (comp(b,a)) h = m - 1;
			else l = m;
			for (; !b[b[0]] && b[0]>1; b[0]--);
			for (i = 1; i <= b[0]; b[i++] >>= 1);
}

int length(const bignum_t a){
	int t,ret;
	for (ret = (a[0] - 1)*DIGIT,t = a[a[0]]; t; t /= 10,ret++);
	return ret>0 ? ret : 1;
}

int digit(const bignum_t a,const int b){
	int i,ret;
	for (ret = a[(b - 1) / DIGIT + 1],i = (b - 1) % DIGIT; i; ret /= 10,i--);
	return ret % 10;
}

int zeronum(const bignum_t a){
	int ret,t;
	for (ret = 0; !a[ret + 1]; ret++);
	for (t = a[ret + 1],ret *= DIGIT; !(t % 10); t /= 10,ret++);
	return ret;
}

void comp(int* a,const int l,const int h,j,t;
	for (i = l; i <= h; i++)
		for (t = i,j = 2; t>1; j++)
			while (!(t%j))
				a[j] += d,t /= j;
}

void convert(int* a,bignum_t b){
	int i,t = 1;
	memset(b,sizeof(bignum_t));
	for (b[0] = b[1] = 1,i = 2; i <= h; i++)
		if (a[i])
			for (j = a[i]; j; t *= i,j--)
				if (t*i>DEPTH)
					mul(b,t),t = 1;
	mul(b,t);
}

void combination(bignum_t a,int m,int n){
	int* t = new int[m + 1];
	memset((void*)t,sizeof(int)*(m + 1));
	comp(t,n + 1,1);
	comp(t,2,m - n,-1);
	convert(t,a);
	delete[]t;
}

void permutation(bignum_t a,int n){
	int i,t = 1;
	memset(a,sizeof(bignum_t));
	a[0] = a[1] = 1;
	for (i = m - n + 1; i <= m; t *= i++)
		if (t*i>DEPTH)
			mul(a,t = 1;
	mul(a,t);
}

#define SGN(x) ((x)>0?1:((x)<0?-1:0))
#define ABS(x) ((x)>0?(x):-(x))

int read(bignum_t a,int &sgn,istream& is = cin){
	char str[MAX*DIGIT + 2],ch,*buf;
	int i,sizeof(bignum_t));
	if (!(is >> str)) return 0;
	buf = str,sgn = 1;
	if (*buf == '-') sgn = -1,buf++;
	for (a[0] = strlen(buf),j = 0; j<DIGIT; j++)
			a[i] = a[i] * 10 + buf[i*DIGIT - 1 - j] - '0';
	for (; !a[a[0]] && a[0]>1; a[0]--);
	if (a[0] == 1 && !a[1]) sgn = 0;
	return 1;
}

struct bignum{
	bignum_t num;
	int sgn;
public:
	inline bignum(){ memset(num,sizeof(bignum_t)); num[0] = 1; sgn = 0; }
	inline int operator!(){ return num[0] == 1 && !num[1]; }
	inline bignum& operator=(const bignum& a){ memcpy(num,a.num,sizeof(bignum_t)); sgn = a.sgn; return *this; }
	inline bignum& operator=(const int a){ memset(num,sizeof(bignum_t)); num[0] = 1; sgn = SGN(a); add(num,sgn*a); return *this; };
	inline bignum& operator+=(const bignum& a){
		if (sgn == a.sgn)add(num,a.num); else if (sgn&&a.sgn){
			int ret = comp(num,a.num); if (ret>0)sub(num,a.num); else if (ret<0){
				bignum_t t;
				memcpy(t,num,sizeof(bignum_t)); memcpy(num,sizeof(bignum_t)); sub(num,t); sgn = a.sgn;
			}
			else memset(num,sizeof(bignum_t)),num[0] = 1,sgn = 0;
		}
		else if (!sgn)memcpy(num,sgn = a.sgn; return *this;
	}
	inline bignum& operator+=(const int a){
		if (sgn*a>0)add(num,ABS(a)); else if (sgn&&a){
			int ret = comp(num,ABS(a)); if (ret>0)sub(num,ABS(a)); else if (ret<0){
				bignum_t t;
				memcpy(t,sizeof(bignum_t)); memset(num,sizeof(bignum_t)); num[0] = 1; add(num,ABS(a)); sgn = -sgn; sub(num,t);
			}
			else memset(num,sgn = 0;
		}
		else if (!sgn)sgn = SGN(a),add(num,ABS(a)); return *this;
	}
	inline bignum operator+(const bignum& a){ bignum ret; memcpy(ret.num,sizeof(bignum_t)); ret.sgn = sgn; ret += a; return ret; }
	inline bignum operator+(const int a){ bignum ret; memcpy(ret.num,sizeof(bignum_t)); ret.sgn = sgn; ret += a; return ret; }
	inline bignum& operator-=(const bignum& a){
		if (sgn*a.sgn<0)add(num,t); sgn = -sgn;
			}
			else memset(num,sgn = 0;
		}
		else if (!sgn)add(num,a.num),sgn = -a.sgn; return *this;
	}
	inline bignum& operator-=(const int a){
		if (sgn*a<0)add(num,ABS(a)); sub(num,sgn = 0;
		}
		else if (!sgn)sgn = -SGN(a),ABS(a)); return *this;
	}
	inline bignum operator-(const bignum& a){ bignum ret; memcpy(ret.num,sizeof(bignum_t)); ret.sgn = sgn; ret -= a; return ret; }
	inline bignum operator-(const int a){ bignum ret; memcpy(ret.num,sizeof(bignum_t)); ret.sgn = sgn; ret -= a; return ret; }
	inline bignum& operator*=(const bignum& a){ bignum_t t; mul(t,a.num); memcpy(num,t,sizeof(bignum_t)); sgn *= a.sgn; return *this; }
	inline bignum& operator*=(const int a){ mul(num,ABS(a)); sgn *= SGN(a); return *this; }
	inline bignum operator*(const bignum& a){ bignum ret; mul(ret.num,a.num); ret.sgn = sgn*a.sgn; return ret; }
	inline bignum operator*(const int a){ bignum ret; memcpy(ret.num,sizeof(bignum_t)); mul(ret.num,ABS(a)); ret.sgn = sgn*SGN(a); return ret; }
	inline bignum& operator/=(const bignum& a){ bignum_t t; div(t,sizeof(bignum_t)); sgn = (num[0] == 1 && !num[1]) ? 0 : sgn*a.sgn; return *this; }
	inline bignum& operator/=(const int a){ int t; div(num,ABS(a),t); sgn = (num[0] == 1 && !num[1]) ? 0 : sgn*SGN(a); return *this; }
	inline bignum operator/(const bignum& a){ bignum ret; bignum_t t; memcpy(t,sizeof(bignum_t)); div(ret.num,a.num); ret.sgn = (ret.num[0] == 1 && !ret.num[1]) ? 0 : sgn*a.sgn; return ret; }
	inline bignum operator/(const int a){ bignum ret; int t; memcpy(ret.num,t); ret.sgn = (ret.num[0] == 1 && !ret.num[1]) ? 0 : sgn*SGN(a); return ret; }
	inline bignum& operator%=(const bignum& a){ bignum_t t; div(t,a.num); if (num[0] == 1 && !num[1])sgn = 0; return *this; }
	inline int operator%=(const int a){ int t; div(num,t); memset(num,t); return t; }
	inline bignum operator%(const bignum& a){ bignum ret; bignum_t t; memcpy(ret.num,sizeof(bignum_t)); div(t,ret.num,a.num); ret.sgn = (ret.num[0] == 1 && !ret.num[1]) ? 0 : sgn; return ret; }
	inline int operator%(const int a){ bignum ret; int t; memcpy(ret.num,t); memset(ret.num,sizeof(bignum_t)); ret.num[0] = 1; add(ret.num,t); return t; }
	inline bignum& operator++(){ *this += 1; return *this; }
	inline bignum& operator--(){ *this -= 1; return *this; };
	inline int operator>(const bignum& a){ return sgn>0 ? (a.sgn>0 ? comp(num,a.num)>0:1) : (sgn<0 ? (a.sgn<0 ? comp(num,a.num)<0 : 0) : a.sgn<0); }
	inline int operator>(const int a){ return sgn>0 ? (a>0 ? comp(num,a)>0:1) : (sgn<0 ? (a<0 ? comp(num,-a)<0 : 0) : a<0); }
	inline int operator>=(const bignum& a){ return sgn>0 ? (a.sgn>0 ? comp(num,a.num) >= 0 : 1) : (sgn<0 ? (a.sgn<0 ? comp(num,a.num) <= 0 : 0) : a.sgn <= 0); }
	inline int operator>=(const int a){ return sgn>0 ? (a>0 ? comp(num,a) >= 0 : 1) : (sgn<0 ? (a<0 ? comp(num,-a) <= 0 : 0) : a <= 0); }
	inline int operator<(const bignum& a){ return sgn<0 ? (a.sgn<0 ? comp(num,a.num)>0:1) : (sgn>0 ? (a.sgn>0 ? comp(num,a.num)<0 : 0) : a.sgn>0); }
	inline int operator<(const int a){ return sgn<0 ? (a<0 ? comp(num,-a)>0:1) : (sgn>0 ? (a>0 ? comp(num,a)<0 : 0) : a>0); }
	inline int operator<=(const bignum& a){ return sgn<0 ? (a.sgn<0 ? comp(num,a.num) >= 0 : 1) : (sgn>0 ? (a.sgn>0 ? comp(num,a.num) <= 0 : 0) : a.sgn >= 0); }
	inline int operator<=(const int a){ return sgn<0 ? (a<0 ? comp(num,-a) >= 0 : 1) : (sgn>0 ? (a>0 ? comp(num,a) <= 0 : 0) : a >= 0); }
	inline int operator==(const bignum& a){ return (sgn == a.sgn) ? !comp(num,a.num) : 0; }
	inline int operator==(const int a){ return (sgn*a >= 0) ? !comp(num,ABS(a)) : 0; }
	inline int operator!=(const bignum& a){ return (sgn == a.sgn) ? comp(num,a.num) : 1; }
	inline int operator!=(const int a){ return (sgn*a >= 0) ? comp(num,ABS(a)) : 1; }
	inline int operator[](const int a){ return digit(num,a); }
	friend inline istream& operator>>(istream& is,bignum& a){ read(a.num,a.sgn,is); return is; }
	friend inline ostream& operator<<(ostream& os,const bignum& a){ if (a.sgn<0)os << '-'; write(a.num,os); return os; }
	friend inline bignum sqrt(const bignum& a){ bignum ret; bignum_t t; memcpy(t,sizeof(bignum_t)); sqrt(ret.num,t); ret.sgn = ret.num[0] != 1 || ret.num[1]; return ret; }
	friend inline bignum sqrt(const bignum& a,bignum& b){ bignum ret; memcpy(b.num,b.num); ret.sgn = ret.num[0] != 1 || ret.num[1]; b.sgn = b.num[0] != 1 || ret.num[1]; return ret; }
	inline int length(){ return ::length(num); }
	inline int zeronum(){ return ::zeronum(num); }
	inline bignum C(const int m,const int n){ combination(num,n); sgn = 1; return *this; }
	inline bignum P(const int m,const int n){ permutation(num,n); sgn = 1; return *this; }
};
/**********************************************/

bignum dp[N][M];

char a[N],b[M];

int n,m;

void clear() {
	for (int i = 0; i <= n; ++i) dp[i][0] = 1;
}

int main() {
	int t;
	cin>>t;
	while (t--) {
		scanf("%s%s",a + 1,b + 1);
		a[0] = b[0] = '&';
		n = strlen(a) - 1;
		m = strlen(b) - 1;
		clear();
		for (int i=1; i<=n;++i) {
			for (int j=1; j<=m;++j) {
				dp[i][j] = dp[i - 1][j];
				if (a[i] == b[j])
					dp[i][j] += dp[i - 1][j - 1];
			}
		}
		cout<<dp[n][m]<<endl;
	}
	return EXIT_SUCCESS;
}