BM算法

#include<stdio.h>#include<stdlib.h>#include<algorithm>#include<string.h>using namespace std;char pattern[10000],str[10000];int last(char *p,char ch){    int length=strlen(p),num=0;    char *pp=p+length+1;    while(pp>=p)    {        if(*pp==ch)        {            return length-num-1;        }        pp--;        num++;    }    return -1;}int bminndex(char *s,char *p){    int n=strlen(s);    int m=strlen(p);    int i=m-1,j=m-1;    while(i<=n-1)    {        if(s[i]==p[j])        {            if(j==0)                return i;            else            {                i--;                j--;            }        }        else        {            i=i+m-min(j,i+last(p,s[i]));            j=m-1;        }    }    return -1;}int sum(char *s,char *p,int m){    int n=bminndex(s+m,p);    return n==-1?0:1+sum(s,p,n+m+1);}int main(){    while(gets(str))    {        printf("%s\n",sum(str,"bkpstor",0)?"warning":"safe");    }    return 0;}