sort a string word by word [closed] - c++

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I was recently doing a problem on string and suddenly this thing came to my mind that, how could i arrange the words of string in increasing order of their ascii values.
for example there's a string:
ab nn ac mm
so the output should be:
ab ac mm nn
actually i want to arrange them according to sum of ascii values of each letter of a word.
like in above example
ab has a sum of (97+98)=195
ac has a sum of (97+99)=196
and so on...
I want to know is there any efficient method of doing it or is there any function in STL which i can use here?
to make the question more clear Here's a second example if a string is-
acd abz
then output is-
acd abz
as sum of ascii of each letter of "acd" is lesser than that of "abz"
acd sums to (97+99+100)=296
abz sums to (97+98+122)=317

Answer 1

For your custom comparison, this code should do it, using a custom comparison function object (functor), i.e. in this case an object that implements bool operator(x,y) for usage in std::sort:
#include <algorithm>
#include <iostream>
#include <iterator>
#include <sstream>
#include <string>
#include <vector>
struct str_comp
{
bool operator()(const std::string &lhs, const std::string &rhs) const
{
return std::accumulate(std::begin(lhs), std::end(lhs), 0) <
std::accumulate(std::begin(rhs), std::end(rhs), 0);
}
};
int main()
{
std::string input_str {"acd abz aaayyyyy zzzaaaaa"};
std::stringstream ss {input_str};
std::vector<std::string> v_str { std::istream_iterator<std::string>{ss}, {} };
std::sort(std::begin(v_str), std::end(v_str), str_comp());
for (const auto& elem : v_str)
std::cout << elem << std::endl;
}
Or, with a lambda function like a boss:
#include <algorithm>
#include <iostream>
#include <iterator>
#include <sstream>
#include <string>
#include <vector>
int main()
{
std::string input_str {"acd abz aaayyyyy zzzaaaaa"};
std::stringstream ss {input_str};
std::vector<std::string> v_str { std::istream_iterator<std::string>{ss}, {} };
std::sort(std::begin(v_str), std::end(v_str),
[](const std::string& lhs, const std::string& rhs)
{
return std::accumulate(std::begin(lhs), std::end(lhs), 0) <
std::accumulate(std::begin(rhs), std::end(rhs), 0);
}
); // end std::sort
for (const auto& elem : v_str)
std::cout << elem << std::endl;
}

Answer 2

You can split the string and push_back in a vector and sort the vector in the following ways:
#include <iostream>
#include <string>
#include <algorithm>
#include <sstream>
#include <vector>
using namespace std;
int main()
{
vector<string>v;
std::string s="ab nn ac mm";
istringstream t(s);
string ss;
while(t>>ss){
v.push_back(ss);
}
sort(v.begin(),v.end());
for (auto i=v.begin(); i!=v.end(); ++i){
cout<<*i<<endl;
}
return 0;
}

Answer 3

I assume your string has only one space, between a word and a word. Also I assume your string is trimed, which means it doesn't have any space in the head and tail of string. Let me show the code.
std::string sort_by_word_code(const std::string &src)
{
if (src.empty())
return "";
typedef std::string::const_iterator const_iterator;
typedef std::tuple<const_iterator, const_iterator, int> WordTuple;
std::vector<WordTuple> words;
const_iterator i = src.begin(), j;
int code;
while (1)
{
code = 0;
for (j = i; j != src.end() && *j != ' '; ++j)
{
code += *j;
}
words.push_back(WordTuple(i, j, code));
if (j == src.end())
break;
i = j + 1;
}
std::sort(words.begin(), words.end(),
[](const WordTuple &t1, const WordTuple &t2) { return std::get<2>(t1) < std::get<2>(t2); }
);
std::string result;
result.reserve(src.size());
for (auto it = words.begin(); ; )
{
result.insert(result.end(),
std::get<0>(*it),
std::get<1>(*it)
);
++it;
if (it == words.end())
break;
result.push_back(' ');
}
return result;
}
(live example)
The idea is simple. Create a vector which has the sum of ascii and begin/end of each word, sort it, and create a result string from it.

Answer 4

Well this code uses common standard functions/algorithms and is (in my opinion) efficient.
The splitting is done by a stringstream as you can see.
#include <algorithm>
#include <iostream>
#include <string>
#include <sstream>
#include <vector>
int main()
{
std::string input = "abz acd";
std::vector<std::string> substrings{ std::istream_iterator<std::string>{ std::stringstream{ input } }, std::istream_iterator<std::string>{} };
std::sort(std::begin(substrings), std::end(substrings),
[](const std::string& a, const std::string& b) -> bool
{
auto calcAscii = [](const std::string& str) -> int
{
int ascii = 0;
for (auto const& it : str)
{
ascii += static_cast<int>(it);
}
return ascii;
};
return calcAscii(a) < calcAscii(b);
});
std::string result;
for (auto const& it : substrings)
{
result += it + " ";
}
std::cout << result;
}