Anagram Problem - Grouping all anagrams [reviewed]

 Question

 Given a list of strings, return a list of lists of strings that groups all anagrams.
  Ex. given {trees, bike, cars, steer, arcs}

  return {{cars, arcs}, {bike}, {tree, steer}}

  m = # of words
  n = length of longest word


   Anagrams are the works with same set of letters but in different orders. This means if we can sort individual words, we can easily find out whether two words are the same.

  3:43 min : to think up the solution. But misunderstood the problems
  13:58 min: to code up the solution based on misunderstanding.
  21 secs: to found out the problem during the verification and fix it up.

  First, I overlooked the problem misled by the keyword, anagram. This should not happen.

  Secondly, did not know C++ solution for string sorting, which I know now. std::sort(begin(), end());


Here is the code in C++.
End of the code.


UPDATE(2019-07-31): solved the question again in python. Got the code right but did not know how to short chars in the string with python. Had to get an help from ipython console.

-
Practice statistic

09:57: to think of algorithm and write up the code
04:40: to fix the sorting logic.

Comments

Post a Comment

Popular posts from this blog

Planting flowers with no adjacent flower plots

Image
Problem Suppose you have a long flowerbed in which some of the plots are planted and some are not. However, flowers cannot be planted in adjacent plots - they would compete for water and both would die. Given a flowerbed (represented as an array containing booleans), return if a given number of new flowers can be planted in it without violating the no-adjacent-flowers rule  Sample inputs  Input: 1,0,0,0,0,0,1,0,0  3 => true  4 => false  Input: 1,0,0,1,0,0,1,0,0  1 => true  2 => false  input: 0  1 => true  2 => false  public boolean canPlaceFlowers(List flowerbed, int numberToPlace) {  // Implementation here  }
Read more
  Given an array of  intervals  where  intervals[i] = [start i , end i ] , merge all overlapping intervals, and return  an array of the non-overlapping intervals that cover all the intervals in the input . Example 1: Input: intervals = [[1,3],[2,6],[8,10],[15,18]] Output: [[1,6],[8,10],[15,18]] Explanation: Since intervals [1,3] and [2,6] overlap, merge them into [1,6]. Example 2: Input: intervals = [[1,4],[4,5]] Output: [[1,5]] Explanation: Intervals [1,4] and [4,5] are considered overlapping.   Constraints: 1 <= intervals.length <= 10 4 intervals[i].length == 2 0 <= start i <= end i <= 10 4
Read more

Find the maximum number of bomb that can be detonated

  Problem You are given a list of bombs. The range of a bomb is defined as the area where its effect can be felt. This area is in the shape of a circle with the center as the location of the bomb. The bombs are represented by a 0-indexed 2D integer array bombs where bombs[i] = [xi, yi, ri]. xi and yi denote the X-coordinate and Y-coordinate of the location of the ith bomb, whereas ri denotes the radius of its range. You may choose to detonate a single bomb. When a bomb is detonated, it will detonate all bombs that lie in its range.  These bombs will further detonate the bombs that lie in their ranges. Given the list of bombs, return the maximum number of bombs that can be detonated if you are allowed to detonate only one bomb. Input: bombs = [[2,1,3],[6,1,4]] Output: 2 Explanation: The above figure shows the positions and ranges of the 2 bombs. If we detonate the left bomb, the right bomb will not be affected. But if we detonate the right bomb, both bombs will be detonated. So...
Read more