字典樹模板

HDU 1251

 

AC代碼

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<string.h>
#include<cmath>
#include<algorithm>
#include<queue>
#include<stack>
#include<deque>
#include<iostream>
using namespace std;
typedef long long  LL;
const int MOD = 1000000007;
const int maxn = 2e6 + 5;


int tree[maxn][30];
int sum[maxn];
int tot;
char ss[maxn];

void insert(char* str)
{
	int len = strlen(str);
	int root = 0;
	for(int i = 0; i < len; i++)
	{
		int id = str[i] - 'a';
		if(!tree[root][id])
			tree[root][id] = ++tot;

		sum[ tree[root][id] ] ++;
		root = tree[root][id];
	}
}


int find(char* str)
{
	int len = strlen(str);
	int root = 0;
	for(int i = 0; i < len; i++)
	{
		int id = str[i] - 'a';
		if(tree[root][id])
		{
			root = tree[root][id];
		}
		else
		{
			return 0;
		}
	}
	return sum[root];
}

int main()
{
	tot = 0;
	while(gets(ss))
	{
		if(ss[0] == '\0')
			break;
		insert(ss);
	}

	while(scanf("%s", ss) != EOF )
	{
		int ans = find(ss);
		printf("%d\n", ans);
	}

	return 0;
}