HDU 1251 求前缀

http://acm.hdu.edu.cn/showproblem.php?pid=1251

基本~

#include<iostream>using namespace std;#define N 500000#define M 26int tree[N][M];int Node;int ans[N];void init(){Node=0;memset(tree[0],0,sizeof(tree[0]));memset(ans,0,sizeof(ans));}void insert(char *p){int len=strlen(p);int root=0;for(int i=0;i<len;i++){int c=p[i]-'a';if(tree[root][c]==0){tree[root][c]=++Node;memset(tree[Node],0,sizeof(Node));}root=tree[root][c];ans[root]++;}}int find(char *p){int len=strlen(p);int root=0;for(int i=0;i<len;i++){int c=p[i]-'a';if(tree[root][c]==0)return 0;root=tree[root][c];}return ans[root];}int main(void){char ch[11];init();while(gets(ch)){if(strlen(ch)==0)break;insert(ch);}while(gets(ch))printf("%d/n",find(ch));}