Re: Read data into c++

From:

axcytz@gmail.com

Newsgroups:

comp.lang.c++

Date:

Fri, 2 Aug 2013 13:00:51 -0700 (PDT)

Message-ID:

<b2635df8-3d85-44fa-9b7a-11b1717f789a@googlegroups.com>

On Friday, August 2, 2013 5:52:32 AM UTC-5, Vlad from Moscow wrote:

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=D0=B7=D0=BE=D0=B2=D0=B0=D1=82=D0=B5=D0=BB=D1=8C axc...@gmail.com =D0=BD=D0=
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Hi all,

I have a data that looks like this:

1,2,3

1,3,4

2,4

2,4,5,6

I have these data in an excel file but can also copy into a txt file. I=

have declared a vector in c++ and want to read these data into my c++ code=
.. For small problems, I typed it manually in my c++ code as:

int init1[] = {1,2,3};

std::vector<int> row1( init1, init1+sizeof(init1)/sizeof(init1[0]))=

;

P.push_back(row1);

int init2[] = {1, 3, 4};

std::vector<int> row2( init2, init2+sizeof(init2)/sizeof(init2[0]))=

;

P.push_back(row2);

and so on.

How can I import these data from txt or excel file?

Thanks

Here is a code snip that demonstrates how the task can be performed

[code]

std::string buffer = "1,2,3\n1,3,4\n2,4\n1\n2,4,5,6";

std::istringstream simulate_file( buffer );

std::string line;

std::vector<std::vector<int>> v;

while ( std::getline( simulate_file, line ) )

{

    std::istringstream is( line );

    std::string s;

    std::vector<int> v1;

    while ( std::getline( is, s, ',' ) ) v1.push_back( std::stoi( s ) );

    v.push_back( v1 );

}

for ( const std::vector<int> &v1 : v )

{

    for ( int x : v1 ) std::cout << x << ' ';

    std::cout << std::endl;

}

[/code]

Thanks Vlad for your help. It seems like in the first line, I should type m=
y data in your code. However, I have at least 200 of those, and it is not e=
fficient to do so. I want to read them from my excel spreadsheet, so I will=
probably need to state my file name, etc, right?