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    <p>First, you should have a matrix/grid/2darray class of some sort</p> <pre><code>//A matrix class that holds objects of type T template&lt;class T&gt; struct matrix { //a constructor telling the matrix how big it is matrix(unsigned columns, unsigned rows) :c(columns), data(columns*rows) {} //construct a matrix from a stream matrix(std::ifstream&amp; stream) { unsigned r; stream &gt;&gt; c &gt;&gt; r; data.resize(c*r); stream &gt;&gt; *this; if (!stream) throw std::runtime_error("invalid format in stream"); } //get the number of rows or columns unsigned columns() const {return c;} unsigned rows() const {return data.size()/c;} //an accessor to get the element at position (column,row) T&amp; operator()(unsigned col, unsigned row) {assert(col&lt;c &amp;&amp; row*c+col&lt;data.size()); return data[data+row*c+col];} protected: unsigned c; //number of columns std::vector&lt;T&gt; data; //This holds the actual data }; </code></pre> <p>And then you simply overload operator&lt;&lt;</p> <pre><code>template&lt;class T&gt; std::istream&amp; operator&gt;&gt;(std::istream&amp; stream, matrix&lt;T&gt;&amp; obj) { //for each row for(int r=0; r&lt;obj.rows(); ++r) { //for each element in that row for(int c=0; c&lt;obj.cols(); ++c) //read that element from the stream stream &gt;&gt; obj(c, r); //here's the magic line! } //as always, return the stream return stream; } </code></pre> <p>Fairly straightforward.</p> <pre><code>int main() { std::ifstream input("input.txt"); int r, c; while(input &gt;&gt; c &gt;&gt; r) { //if there's another line matrix&lt;char&gt; other(c, r); //make a matrix if (!(input &gt;&gt; other)) //if we fail to read in the matrix break; //stop //dostuff } //if we get here: invalid input or all done } </code></pre>
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    1. COThanks, really useful, but can you comment it a bit? Since I'm having some difficulty understanding the first part.
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    2. CO@Link: Done. Keep in mind, your actual matrix class should probably have more methods, iterators, and other such. I go over members that containers should have [here](http://stackoverflow.com/a/7759622/845092)
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    3. COSo, on usage, do I just open the file and do something like file >> array?
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