RosettaCodeData/Task/Knuth-shuffle/Vedit-macro-language/knuth-shuffle.vedit
Ingy döt Net d066446780 langs a-z
2013-04-10 22:43:41 -07:00

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Text

// Test main
#90 = Time_Tick // seed for random number generator
#99 = 20 // number of items in the array
IT("Before:") IN
for (#100 = 0; #100 < #99; #100++) {
#@100 = #100
Num_Ins(#@100, LEFT+NOCR) IT(" ")
}
IN
Call("SHUFFLE_NUMBERS")
IT("After:") IN
for (#100 = 0; #100 < #99; #100++) {
Num_Ins(#@100, LEFT+NOCR) IT(" ")
}
IN
Return
//--------------------------------------------------------------
// Shuffle numeric registers #0 to #nn
// #99 = number of registers to shuffle (nn-1)
//
:SHUFFLE_NUMBERS:
for (#91 = #99-1; #91 > 0; #91--) {
Call("RANDOM")
#101 = Return_Value
#102 = #@101; #@101 = #@91; #@91 = #102
}
Return
//--------------------------------------------------------------
// Generate random numbers in range 0 <= Return_Value < #91
// #90 = Seed (0 to 0x7fffffff)
// #91 = Scaling (0 to 0x10000)
//
:RANDOM:
#92 = 0x7fffffff / 48271
#93 = 0x7fffffff % 48271
#90 = (48271 * (#90 % #92) - #93 * (#90 / #92)) & 0x7fffffff
Return ((#90 & 0xffff) * #91 / 0x10000)