38. April 1, 2014 ad search interview questions in 360

360 of the Headquarters was located near Wangjing 798 in Beijing. A friend went to the interview this week and gave a general talk about the process.

360 there is a lobby on the first floor of the headquarters, and there are a lot of MM at the front desk, indicating the intention. It is directed to the interview area (there are quite a lot of people, there should be very few people, or there should be new projects ).

Side:

Technically, he is a younger brother.

1) Introduce Yourself

2) I spoke about several important projects and asked about the projects. These are all topics of interest to the interviewer.

3) a programming question is given: design a trie tree to create a trie tree and search functions. The data is a batch of English words, all of which are lowercase letters.

Analysis:

This topic mainly involves three aspects: design the data structure of the trie tree, implement the trie tree creation function, and search for English words to see if they exist.

The implementation is as follows:

#include<iostream>#include<string.h>using namespace std;#define MAXNODE 26struct TrieNode{        int counts;        TrieNode* next[MAXNODE];//next character        TrieNode():counts(1){                int i = 0;                while(i < MAXNODE)                {                        next[i++] = NULL;                }        }};void createTrie(TrieNode* &root, char* str){        if(strlen(str) <= 0) return;        if(root == NULL)                root = new TrieNode();        int i = 0;        TrieNode* p = root;        while(i < strlen(str))        {                int k = str[i++] - 'a';                if(p->next[k])                {                        p->next[k]->counts ++;                }                else                        p->next[k] = new TrieNode();                p = p->next[k];        }}int SearchTrie(TrieNode* root, char* str){        TrieNode* p = root;        if(p == NULL) return -1;        int i = 0;        while(i < strlen(str))        {                int k = str[i++] - 'a';                if(p->next[k] == NULL)                        return 0;                else                        p = p->next[k];                if(i == strlen(str))                        return p->counts;        }}int main(){        char a[][4] = {"abc", "bcd", "ade", "acd", "bgf"};        int i = 0;        int j = 0;        TrieNode* root = NULL;        while(i < 5)        {                createTrie(root, a[i++]);        }        char* b = "bcd";        int in = SearchTrie(root, b);        if( in <= 0)                cout << "Trie can't find \"" << b << "\"" << endl;        else                cout << "Trie have find \"" << b << "\"" << endl;        return 0;}

Output result:

Trie have find "bcd"

Summary:

This algorithm can be used for string prefix queries, such as searching TIPS.