Date : 22 December 2020

# Aptitude

A packet of sweets was distributed among 10 children and each of them received 4 sweets. If it is distributed among 8 children, how many sweets will each child get?

• 4

• 5

• 6

• 7

Ans: 5

# Technical MCQ

Which of the following statement is true?

• DELETE does not free the space containing the table and TRUNCATE free the space containing the table

• Both DELETE and TRUNCATE free the space containing the table

• Both DELETE and TRUNCATE does not free the space containing the table

• DELETE free the space containing the table and TRUNCATE does not free the space containing the table

Ans: DELETE does not free the space containing the table and TRUNCATE free the space containing the table

Explanation: The SQL TRUNCATE command is used to delete all the rows from the table and free the space containing the table.

# Coding

Write a function to find the longest common prefix string amongst an array of strings.

If there is no common prefix, return an empty string "".

Example 1:

`Input: strs = ["flower","flow","flight"]​Output: "fl"`

Example 2:

`Input: strs = ["dog","racecar","car"]​Output: "" //Explanation: There is no common prefix among the input strings.`

## Solution:

`struct Trie{        unordered_map<char,Trie*> child;        bool isword=false;    }root;    void insert(string word){        auto cur=&root;        for(char c : word){            if(cur->child.find(c)==cur->child.end())                cur->child[c]=new Trie();            cur=cur->child[c];        }        cur->isword=true;    }    string longestCommonPrefix(vector<string>& strs) {        if(strs.size()==0) return "";        for(auto word:strs)            insert(word);        auto cur=&root;        string res="";        while(cur&&!cur->isword&&(cur->child.size()==1)){            auto it=cur->child.begin();            res+=it->first;            cur=it->second;        }        return res;    }`