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Message: [QUOTE="Your Uncle, post: 2470753"] About a month ago, Heathfield posted the peudosource for random permuting from TAOCP. It was all of maybe five lines. You needed to be able to do two things: be able to get a random number in a range and swap. I remembered that Dan Pop taught me to write the swap as a macro. With forum improvements, this became: #define SWAP(m, n) (tmp = (m), (m) = (n), (n) = tmp) The random number comes, again with forum improvements: int rand_in_range(int m, int n) { /*seed srand in main */ /* [m, n] is range */ int roll_again_threshold, divisor, result, tmp, offset, num_results; if (m>n) SWAP(m, n); offset = m; num_results = n - m + 1; if (num_results == 1) { return m; } roll_again_threshold = RAND_MAX - RAND_MAX%num_results; divisor = roll_again_threshold/num_results; do { result = rand(); } while (result >= roll_again_threshold); result /= divisor; return offset + result; } But then I starting thinking, and that is, of course, where the trouble began. I posted elsewhere, and I don't think you need much of a language background to get the gist of it: Ich habe zwei Funktionen bei file scope erklaert: void permute_string(char * m, int n); void permute_int(int * m, int n); Sie tun das genau Gleiche, allerdings erstere mit chars und letztere mit ints. Wie werden diese Funktionen Eine? Basically, how do I take 2 functions that differ only in the type they operate on, and make them one? I was advised to use: void permute (void *data, int n, size_t elsize); that could be called for an array a with permute(a, sizeof a / sizeof a[0], sizeof a[0]); Is this going to work? If it isn't, then the idea is mine. If it will then it's Erich Fruehstueck's. cheers, furunculus [/QUOTE]

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