hdu 3065
題目大意:
給出n個模式串，最後給出主串
問有模式串在主串中出現的次數
解題思路:
ac自動機建立字典樹的用w值標記第幾個模式串
定義k值，匹配時若字典樹中的某個結點不等於k且w不為0則記錄該點
有多個主串需要匹配，所以不需要改變w的值，但可以判斷k的值
若該失敗指標的結點k值已經被匹配過則不需要再次匹配
**:
#include #include #include #define max 52
struct snodetree[max*1010];
int index,visit[1010],listb[1000001];
char ch[2000010],ch1[1010][max];
void insert(int star,int tlen,int k) //建立字典樹
else
s=tree[s].next[child];
}}void build_fail(int star) //建立失敗指標
now_fail=tree[now_fail].fail;
}if(now_fail==-1)
tree[tree[tempv].next[i]].fail=0;
listb[s++]=tree[tempv].next[i];}}
}}int ac_auto(int tlen) //bfs匹配
child=ch[i-1]-'a';
while(p!=0&&tree[p].next[child]==-1)
p=(tree[p].next[child]==-1)?0:tree[p].next[child];
temp=p;
while(temp!=0&&tree[temp].w!=-1) //記錄出現的次數
}return sum;
}int main()
build_fail(0); //建立失敗指標
getchar();
gets(ch); //主串可能有空格
k=ac_auto(strlen(ch)); //匹配
for(i=1;i<=n;i++)}}
return 0;
}
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