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POC++ Newbie needs helps for printing combinations of integers
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  1. POC++ Newbie needs helps for printing combinations of integers
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    copied!<p>Suppose I am given:</p> <ol> <li>A range of integers <code>iRange</code> (i.e. from <code>1</code> up to <code>iRange</code>) and</li> <li>A desired number of combinations</li> </ol> <p>I want to find the number of all possible combinations and print out all these combinations.</p> <p>For example:</p> <p><strong>Given</strong>: <code>iRange = 5</code> and <code>n = 3</code></p> <p>Then the number of combinations is <code>iRange! / ((iRange!-n!)*n!) = 5! / (5-3)! * 3! = 10</code> combinations, and the output is:</p> <pre><code>123 - 124 - 125 - 134 - 135 - 145 - 234 - 235 - 245 - 345 </code></pre> <p>Another example:</p> <p><strong>Given</strong>: <code>iRange = 4</code> and <code>n = 2</code></p> <p>Then the number of combinations is <code>iRange! / ((iRange!-n!)*n!) = 4! / (4-2)! * 2! = 6</code> combinations, and the output is:</p> <pre><code>12 - 13 - 14 - 23 - 24 - 34 </code></pre> <p>My attempt so far is:</p> <pre><code>#include &lt;iostream&gt; using namespace std; int iRange= 0; int iN=0; int fact(int n) { if ( n&lt;1) return 1; else return fact(n-1)*n; } void print_combinations(int n, int iMxM) { int iBigSetFact=fact(iMxM); int iDiffFact=fact(iMxM-n); int iSmallSetFact=fact(n); int iNoTotComb = (iBigSetFact/(iDiffFact*iSmallSetFact)); cout&lt;&lt;"The number of possible combinations is: "&lt;&lt;iNoTotComb&lt;&lt;endl; cout&lt;&lt;" and these combinations are the following: "&lt;&lt;endl; int i, j, k; for (i = 0; i &lt; iMxM - 1; i++) { for (j = i + 1; j &lt; iMxM ; j++) { //for (k = j + 1; k &lt; iMxM; k++) cout&lt;&lt;i+1&lt;&lt;j+1&lt;&lt;endl; } } } int main() { cout&lt;&lt;"Please give the range (max) within which the combinations are to be found: "&lt;&lt;endl; cin&gt;&gt;iRange; cout&lt;&lt;"Please give the desired number of combinations: "&lt;&lt;endl; cin&gt;&gt;iN; print_combinations(iN,iRange); return 0; } </code></pre> <p><strong>My problem:</strong> The part of my code related to the printing of the combinations works only for <code>n = 2, iRange = 4</code> and I can't make it work in general, i.e., for any <code>n</code> and <code>iRange</code>.</p>
 

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