KMP&&EKMP&&Manacher算法模版

#include<iostream>#include<cstdio>#include<cstdlib>#include<cstring>#include<string>#include<queue>#include<algorithm>#include<map>#include<iomanip>#define INF 99999999using namespace std;const int MAX=100000+10;char a[MAX],b[MAX];int next[MAX],extend[MAX],p[MAX];/******************************************************************************/KMP:void get_next(char *a,int len){int i=-1,j=0;next[0]=-1;while(j<len){if(i == -1 || a[i] == a[j]){if(a[++i] == a[++j])next[j]=next[i];//如果需要用到next的性质就不要用这一步优化,这一步主要是在KMP时:a[j] != b[k],a[j] == a[i],j=next[j]=next[i]else next[j]=i;}else i=next[i];}}int KMP(char *a,char *b){int lena=strlen(a),lenb=strlen(b),i=0,j=0;get_next(a,lena);while(j<lenb && i<lena){if(i == -1 || a[i] == b[j])++i,++j;else i=next[i];}return i;//i == lena表示a是b的字串 }/******************************************************************************/Manacher:void manacher(char *s){int len=strlen(s);for(int i=len;i>=0;--i){s[i+i+2]=s[i];s[i+i+1]='#';}s[0]='*';int k=1,maxlen=0;for(int i=2;i<len+len+1;++i){int maxr=k+p[k]-1;p[i]=min(p[2*k-i],max(maxr-i+1,1));while(s[i-p[i]] == s[i+p[i]])++p[i];if(i+p[i]>k+p[k])k=i;if(p[i]>maxlen)maxlen=p[i];}}/******************************************************************************/EKMP:void get_next(char *a,int len){int k=0,i=1;next[0]=len;while(k<len && a[k] == a[k+1])++k;next[1]=k;k=1;while(++i<len){int maxr=k+next[k]-1;next[i]=min(next[i-k],max(maxr-i+1,0));while(i+next[i]<len && a[next[i]] == a[i+next[i]])++next[i];if(i+next[i]>k+next[k])k=i;}}void EKMP(char *a,char *b){int lena=strlen(a),lenb=strlen(b),k=0,i=0;get_next(a,lena);b[lenb]='*';//b[lenb]重置为a,b里没出现的字符 while(a[k] == b[k])++k;//如果没有重置b[lenb],应为k<lenb && a[k] == b[k] extend[0]=k;k=0;while(++i<lenb){int maxr=k+extend[k]-1;extend[i]=min(next[i-k],max(maxr-i+1,0));while(a[extend[i]] == b[i+extend[i]])++extend[i];//如果没有重置b[lenb],需判断i+extend[i]<lenbif(i+extend[i]>k+extend[k])k=i;}}/******************************************************************************/int main(){while(cin>>a>>b){KMP(a,b);manacher(a);EKMP(a,b);}return 0;}