c++ : printing wired string - c++

Question

I'm converting a string to char array and than back to a string and into a vector.
When I'm trying to print I'm getting this:
this
is
the
sentence iuִִ[nu#h?(h????X
and much more. This is the code:
int main(int argc, char *argv[]){
string s ="this is the sentence";
char seq[sizeof(s)];
strcpy(seq, "this is the sentence");
vector<string> vec = split(seq);
printWords(vec);
return 0;
}
And this is the func.cpp file. One function splits the char to string vector, the other is printing:
vector<string> split(char sentence[]){
vector<string> vecto;
int i=0;
int size= strlen(sentence);
while((unsigned)i< size){
string s;
char c =' ';
while(sentence[i]!=c){
s=s+sentence[i];
i+=1;
}
vecto.push_back(s);
i+=1;
}
return vecto;
}
void printWords(vector<string> words){
int i=0;
while ((unsigned)i<words.size()){
string s = words.at(i);
cout << words.at(i) << endl;
i+=1;
}
}

Answer 1

After understanding the answer above, try a less error-prone style, something more like this (C++11):
#include <iostream>
#include <sstream>
#include <vector>
using namespace std;
int main(){
string s{"this is the sentence"};
stringstream sStream;
sStream<<s;
string word;
vector<string> vec;
while(sStream >> word){
vec.emplace_back(word);
}
for(auto &w : vec){
cout << "a word: " << w <<endl;
}
}

Answer 2

One of your issues is that sizeof(s) != s.size().
Try this:
char letters = new char[s.size() + 1]; // +1 for the null terminator.
The expression sizeof(s) returns the size of the std::string object, not the quantity of characters in the string. The std::string object may be more than the string contents.
Also, try using std::string::operator[] to access individual characters in the string.
Example:
string s = "this is it";
char c = s[5]; // returns 'i' from "is".
You should also consider using the search functions of std::string, such as std::string::find_first_of.
Example:
unsigned int position = s.find_first_of(' ');
Another useful function is the substr method:
std::string word = s.substr(0, position);