Please help translate c++ into matlab code!

Can anyone help me translate this c++ code into matlab code? I can't seem to get the hang of using string in matlab compared to c++, been sitting around it for ages now. Edit: the program I'm trying to do is that it outputs all possibilities to put + or − or nothing between the numbers from 1 to 9 (in ascending order) such that the result is some target number. The target number is entered by the user. Say for target number 100, one of the possibilities is: 1+2+3−4+5+6+78+9=100.

#include <iostream>
#include <sstream>
#include <string>
#include <vector>
# include <iomanip>
# include <cmath>
# include <fstream>
# include <cstring>

using namespace std;

int main()
{
   int TARGET;
   cin >> TARGET;

   int i, total;
   vector<string> all = { "1" };                 // Will hold all 3^8 legitimate combinations as a string

   for ( i = 2; i <= 9; i++ )                    // Add each following digit with either -, + or nothing
   {
      char c = (char)( '0' + i );
      vector<string> temp;
      for ( string s : all )                     // For each previous string there will be three new ones
      {
         temp.push_back( s + '-' + c );
         temp.push_back( s + '+' + c );
         temp.push_back( s + c );
      }
      all = temp;
   }

   // Now evaluate results by stringstreaming +n or -n into integers
   vector<string> matches;
   for ( string s : all )
   {
      stringstream ss( s );
      ss >> total;
      while ( ss >> i ) total += i;
      if ( total == TARGET ) matches.push_back( s );
   }

   // Write results
   cout << "There are " << matches.size() << " possibilities:\n";
   for ( string s : matches ) cout << s << '\n';
}

[Ameer Hamza]

Instead of pasting the code, it would be much better if you can explain what you are trying to do in this code. Understanding someone else's code requires much more effort. In the end, it will not be a line to line translation anyway. MATLAB will usually be able to do it in a few lines.

Answer 1

[Ameer Hamza]

Try this. It tries all combinations of the symbols to find the required ones

clear
nums = num2str((1:9)')'; % '1234...9'
symbols = '+ -'; % space is used for empty symbol, it will be later ignored

x = repmat({symbols}, 1, 8); % total number of symbols are 8
symbols_combs = char(combvec(x{:})'); % create combinations of all symbols

exprs(:,2:2:16) = symbols_combs; % all possible expressions
exprs(:,1:2:17) = repmat(nums, size(exprs,1), 1);
exprs = mat2cell(exprs, ones(size(exprs,1),1), size(exprs,2));
exprs = cellfun(@(x) {strrep(x, ' ', '')}, exprs);

values = cellfun(@(x) str2num(x), exprs); % convert the char array to values
mask = values == 100;

final_exprs = exprs(mask);

Result:

>> final_exprs
final_exprs =
  11×1 cell array
    {'1+23-4+56+7+8+9' }
    {'12+3-4+5+67+8+9' }
    {'1+2+3-4+5+6+78+9'}
    {'1+2+34-5+67-8+9' }
    {'12-3-4+5-6+7+89' }
    {'123-45-67+89'    }
    {'12+3+4+5-6-7+89' }
    {'123+4-5+67-89'   }
    {'123+45-67+8-9'   }
    {'123-4-5-6-7+8-9' }
    {'1+23-4+5+6+78-9' }

[Ameer Hamza]

You can add breakpoints and go through the code line by line. Also read the documentation of the functions involved in this code. It will help you to understand the purpose of each line.