Question

I need only one  C++ function . It's C++ don't write any other language.

Hello I need unzip function here is my zip function below. So I need the opposite function unzip.

Instructions:

The next tools you will build come in a pair, because one (zip) is a file compression tool, and

the other (unzip) is a file decompression tool.

The type of compression used here is a simple form of compression called run-length encoding (RLE). RLE is quite simple: when you encounter n characters of the same type in a row, the compression tool (zip) will turn that into the number n and a single instance of the character.

Thus, if we had a file with the following contents: 10a4b
the tool or unzip
Requirements wcat is passed in a file and will output the file on the terminal (use cat to familiarize yourself with how this should work) • wgrep is passed 2 arguments, the first is the word or words that the user is looking for and the second argument is the file that should be searched (use grep to familiarize yourself with this) • wzip is passed a text file and redirects it to a compressed zip file • wunzip is passed a zip file and prints out the unzipped file in standard output
function would turn it (logically) into:
aaaaaaaaaabbbb

So write the C++ unzip function that will turn 10a4b into aaaaaaaaaabbbb opposite of zip function. I'll make a txt file example like file.txt that will have 10a4b text once I will run your unzip function it will turn into aaaaaaaaaabbbb. I tested my zip function on terminal and it's working perfectly.

here is my zip function:

Full program with zip funcion with output

#include<iostream>
#include<string>
#include<fstream>

using namespace std;
string zip(const string & str)
{
   int i = str.size();
   string enc;

   for (int j = 0; j < i; ++j) {
       int count = 1;
       while (str[j] == str[j + 1]) {
           count++;
           j++;
       }
       enc += std::to_string(count);
       enc.push_back(str[j]);
   }
   return enc;
}
int main(int argc, char *argv[])
{
   ifstream in;
       // one argument
       if (argc<2) {
           cout << "Please enter command";
               return(-1);
       }
   // two arguments
   if (argc<3) {
       cout << "Please enter file name";
       return(-1);
   }
   in.open(argv[2]);
   if (in.bad()) {
       cout << "File not found";
       return(-1);
   }
   string line;
   // read each line
   while (getline(in, line))
   {
       // decode line
       string encode = zip(line);
       // print line
       cout << encode << endl;
   }
   return(0);
}

Answer 1

#include<iostream>
#include<string>
#include<fstream>
using namespace std;
string unzip(const string & str)
{
int i = str.size(),l=0;
string dec;
for (int j = 0; j < i; ++j) {
if(isdigit(str[j]))
l=l*10+(str[j]-'0');
else
{
for(int k=0;k<l;++k)
dec.push_back(str[j]);
l=0;
}
}
return dec;
}
int main(int argc, char *argv[])
{
ifstream in;
// one argument
if (argc<2) {
cout << "Please enter command";
return(-1);
}
// two arguments
if (argc<3) {
cout << "Please enter file name";
return(-1);
}
in.open(argv[2]);
if (in.bad()) {
cout << "File not found";
return(-1);
}
string line;
// read each line
while (getline(in, line))
{
// decode line
string decode = unzip(line);
// print line
cout << decode << endl;
}
return(0);
}