Could you spot the error in my code?

[robezy]

Hi,

I'm trying to convert a 2d array given in the form of strings to integer 2d arrays.

ie, the array will be given as a vector of strings and i need to get it in 2d int vector.

But, the last column of the 2d array is missing in the converted matrix.

I suspect the error is in the following code, but unable to spot any. Please help.

vector< vector<int> > IntMatrix;
			vector<string>::iterator vsitr;
			string::iterator sitr;
			
			for(vsitr=strmat.begin();vsitr != strmat.end(); vsitr++)
			{
				vector<int> row;
				for(sitr=vsitr->begin(); sitr+1  != vsitr->end(); sitr = sitr +2)
				{
					row.push_back(*(sitr) - '0');
				}
				IntMatrix.push_back(row);
			}
			return IntMatrix;

specifically at

for(sitr=vsitr->begin(); sitr+1  != vsitr->end(); sitr = sitr +2)
{
        row.push_back(*(sitr) - '0');
}

The entire code is below if you need to check it.

#include <string>
#include <vector>
#include <algorithm>
using namespace std;

class TallPeople
{
	public: 
		vector <int>  getPeople(vector <string> people)
		{
			vector<int> result;
			vector<int> inter;
			vector< vector <int> > matrix = convert(people);
			
			//calculate tallest of the shortest
			vector< vector<int> >::iterator vvitr;
			for(vvitr=matrix.begin();vvitr != matrix.end(); vvitr++)
			{
				vector<int> vint;
				vint.assign(vvitr->begin(), vvitr->end());
				inter.push_back(*min_element(vint.begin(),vint.end()));
			}
			result.push_back(*max_element(inter.begin(),inter.end()));
			
			//calculate shortest of the tallest
			inter.erase(inter.begin(), inter.end());
			for(int i=0 ;i < matrix[0].size(); i++)
			{
				int maxi=0;
				for(int j=0; j < matrix.size();j++)
					maxi = max(maxi, matrix[j][i]);
				inter.push_back(maxi);		
			}
				
			result.push_back(*(min(inter.begin(), inter.end())));
			return inter;
		}
	private:
		vector< vector<int> > convert(vector <string> strmat)
		{
			vector< vector<int> > IntMatrix;
			vector<string>::iterator vsitr;
			string::iterator sitr;
			
			for(vsitr=strmat.begin();vsitr != strmat.end(); vsitr++)
			{
				vector<int> row;
				for(sitr=vsitr->begin(); sitr+1  != vsitr->end(); sitr = sitr +2)
				{
					row.push_back(*(sitr) - '0');
				}
				IntMatrix.push_back(row);
			}
			return IntMatrix;
		}	
	
};

The input format is as below

Each element of people will be a single space-delimited list of positive integers such that:
1) Each positive integer is between 1 and 1000 inclusive with no extra leading zeros.
2) Each element contains the same number of integers.
3) Each element contains at least 2 positive integers.
4) Each element does not contain leading or trailing whitespace.

Thanks

[screw]

Would you write an example string (which there are in the string vector in convert fnc)?

You said:
2) Each element contains the same number of integers.

But this command row.push_back(*(sitr) - '0'); convert only individual characters and not entirely number.

I think a string for example "1000" then *(sitr) - '0' command makes 4 individual integers which contains 1, 0, 0, 0 values.

[robezy]

This is problem from topcoder site. You can see the question here and sample inputs at

http://www.topcoder.com/stat?c=problem_statement&pm=2923&rd=5854.

And I haven't thought about the point you mentioned, i considered only one digit numbers. So, my solution will not scale I guess. I will need to rewrite my code.

I solved above mentioned issue, by rewriting my code as below

for(sitr=vsitr->begin(); sitr  != vsitr->end(); sitr++)
{
       if( *sitr != ' ')
                   row.push_back(*(sitr) - '0');
}

but still dont get, why above code didnot work.

[robezy]

A sample given in the site is pasted below, in case youd dont have topcoder login

{"1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20", "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20"}

[screw]

You can convert the numbers from string to integer very simply:

#include <string>
#include <iostream>
#include <sstream>

using namespace std;


int main(int argc, char *argv[])
{
    string s = "1234  11  38 1234567";
    stringstream ss;
    ss << s;
    int n = 0;

    do
    {
         ss >> n;
         cout << n << endl;
    }while( ss.good() );

    return 0;
}

You get this outcome (in integer variables of course):

1234
11
38
1234567

[robezy]

Hi,

thanks for this intput. I never used sstream before. So couldn't think this way. Quite easy i guess.