Data commit

Task/Knuth-shuffle/M4/knuth-shuffle.m4

@@ -0,0 +1,27 @@
+divert(-1)
+define(`randSeed',141592653)
+define(`rand_t',`eval(randSeed^(randSeed>>13))')
+define(`random',
+   `define(`randSeed',eval((rand_t^(rand_t<<18))&0x7fffffff))randSeed')
+define(`for',
+   `ifelse($#,0,``$0'',
+   `ifelse(eval($2<=$3),1,
+   `pushdef(`$1',$2)$4`'popdef(`$1')$0(`$1',incr($2),$3,`$4')')')')
+define(`set',`define(`$1[$2]',`$3')')
+define(`get',`defn($1[$2])')
+define(`new',`set($1,size,0)')
+define(`deck',
+   `new($1)for(`x',1,$2,
+         `set(`$1',x,x)')`'set(`$1',size,$2)')
+define(`show',
+   `for(`x',1,get($1,size),`get($1,x)`'ifelse(x,get($1,size),`',`, ')')')
+define(`swap',`set($1,$2,get($1,$4))`'set($1,$4,$3)')
+define(`shuffle',
+   `define(`s',get($1,size))`'for(`x',1,decr(s),
+      `swap($1,x,get($1,x),eval(x+random%(s-x+1)))')')
+divert
+
+deck(`b',52)
+show(`b')
+shuffle(`b')
+show(`b')