POJ3461:Oulipo

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http://poj.org/problem?id=3461

题目很简单，就是寻找给定的模式串在目标串中出现了多少次，采用KMP算法。代码如下：

/*ID: csuchenanAlgorithm: KMPPROG: POJ 3461 OulipoLANG: C++*/#include<iostream>#include<string.h>#include<stdio.h>#include<string>using namespace std ;const int maxn = 10005 ;int  next[maxn] ;char patt[maxn] ;string term ;void init()  ;void KMP_match() ;int main(){int n ;cin>>n ;cin.ignore() ;while(n--){cin.getline(patt + 1 , sizeof(patt) - 1) ;getline(cin , term) ;memset(next , 0 , sizeof(next)) ;init()  ;KMP_match() ;}return 0 ;}void init(){int i ;int k ;int len = strlen(patt + 1) ;next[1] = 0 ;k = 0 ;for(i = 2 ; i <= len ; i ++){while(k > 0 && patt[k + 1] != patt[i])k = next[k] ;if(patt[k+1] == patt[i])k ++ ;next[i] = k ;}}void KMP_match(){int lenp = strlen(patt + 1) ;int lent = term.size() ;int i = 0 ;int q ;int ncount ;ncount = 0 ;q = 0 ;for(i = 0 ; i < lent ; i ++){while(q > 0 && patt[q+1] != term[i] )q = next[q] ;if(patt[q+1] == term[i])q = q + 1 ;if(q == lenp){q = next[q] ;ncount ++ ;}}cout<<ncount<<endl ;}