CODEWITHSUNDEEP
c++
SILO
SILO

Reputation: 73

sort() error even when including <algorithm>

I have also copied the exact code from Programming Principles & Practice but to no avail. I get an error message when I try to use std::sort(word) or sort(word):

<source>: In function 'int main()':
<source>:13:14: error: no matching function for call to 'sort(std::vector<std::__cxx11::basic_string<char> >&)'
   13 |     std::sort(words);
      |     ~~~~~~~~~^~~~~~~
[...]

The code:

#include <iostream>
#include <vector>
#include <algorithm>

int main()
{
    std::vector<std::string> words;
    for(std::string temp; std::cin >> temp;){
        words.push_back(temp);
    }
    std::cout << "Number of words: " << words.size() << "\n";

    std::sort(words);

     for(int i=0; i < words.size(); i++){
        if(i == 0; words[i-1]!=words[i]){
            std::cout << words[i] << "\n";
        }
    }
}

Upvotes: 1

Views: 176

Answers (2)

Shubham Garg
Shubham Garg

Reputation: 517

sort function accepts either 2 or 3 variables. first 2 are for starting and ending indexes. In this case, they are words.begin() and words.end()

So, your 13th line (which has the error) should be:

std::sort(words.begin(),words.end());

The 3rd argument can be given to specify type of sort. For example,

std::sort(words.begin(),words.end(),greater<int>());

will sort the vector in reverse order.

Upvotes: 2

Jabberwocky
Jabberwocky

Reputation: 50774

There are two problems in your code:

  1. your usage of sort is wrong, it's std::sort(words.begin(), words.end()). This should be in your book or in your learning material.

  2. in if (i == 0; words[i-1]!=words[i]) during the first iteration i is 0 and therefore you are accessing words[-1] which is out of bounds and which will at best trigger some error message. Also the ; makes no sense here.

You probably want this:

  for (size_t i = 0; i < words.size() - 1; i++) {
    if (words[i] != words[i + 1]) {
      std::cout << words[i] << "\n";
    }
  }

Upvotes: 3

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