对参加ACM竞赛非常有用的几个ACM答题模板（数论，数值计算，NP等等）

#include <iostream.h> #include <string.h> #define DIGIT 4 #define DEPTH 10000 #define MAX 100 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,0,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,i++,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 c,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,a[i]-=(a[i]-DEPTH+1)/DEPTH*DEPTH,i++); for (;!a[a[0]]&&a[0]>1;a[0]--); } void mul(bignum_t c,const bignum_t a,const bignum_t b){ int i,j; memset((void*)c,0,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[a[0]]%=DEPTH,a[0]++); for (;!a[a[0]]&&a[0]>1;a[0]--); } void mul(bignum_t b,const bignum_t a,const int c,const int d){ int i; memset((void*)b,0,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,0,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,m,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,l,m,i; memset((void*)b,0,sizeof(bignum_t)); for (i=b[0]=(a[0]+1)>>1;i;sub(a,b,m,i-1),b[i]+=m,i--) for (h=DEPTH-1,l=0,b[i]=m=(h+l+1)>>1;h>l;b[i]=m=(h+l+1)>>1) if (comp(b,m,i-1,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,const int d){ int i,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,const int h,bignum_t b){ int i,j,t=1; memset(b,0,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,0,sizeof(int)*(m+1)); comp(t,n+1,m,1); comp(t,2,m-n,-1); convert(t,m,a); delete []t; } void permutation(bignum_t a,int m,int n){ int i,t=1; memset(a,0,sizeof(bignum_t)); a[0]=a[1]=1; for (i=m-n+1;i<=m;t*=i++) if (t*i>DEPTH) mul(a,t),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,j; memset((void*)a,0,sizeof(bignum_t)); if (!(is>>str)) return 0; buf=str,sgn=1; if (*buf=='-') sgn=-1,buf++; 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]--); if (a[0]==1&&!a[1]) sgn=0; return 1; } struct bignum{ bignum_t num; int sgn; public: inline bignum(){memset(num,0,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,0,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,a.num,sizeof(bignum_t));sub(num,t);sgn=a.sgn;}else memset(num,0,sizeof(bignum_t)),num[0]=1,sgn=0;}else if(!sgn)memcpy(num,a.num,sizeof(bignum_t)),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,num,sizeof(bignum_t));memset(num,0,sizeof(bignum_t));num[0]=1;add(num,ABS(a));sgn=-sgn;sub(num,t);}else memset(num,0,sizeof(bignum_t)),num[0]=1,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,num,sizeof(bignum_t));ret.sgn=sgn;ret+=a;return ret;} inline bignum operator+(const int a){bignum ret;memcpy(ret.num,num,sizeof(bignum_t));ret.sgn=sgn;ret+=a;return ret;} inline bignum& operator-=(const bignum& a){if(sgn*a.sgn<0)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,a.num,sizeof(bignum_t));sub(num,t);sgn=-sgn;}else memset(num,0,sizeof(bignum_t)),num[0]=1,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));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,num,sizeof(bignum_t));memset(nu