Kolakoski sequence: Difference between revisions

Added D
(Added Go)
(Added D)
Line 160:
Possible Kolakoski sequence? False
</pre>
 
=={{header|D}}==
{{trans|Kotlin}}
<lang d>import std.stdio;
 
void repeat(int count, void delegate(int) action) {
for (int i=0; i<count; i++) {
action(i);
}
}
 
T nextInCycle(T)(T[] self, int index) {
return self[index % self.length];
}
 
T[] kolakoski(T)(T[] self, int len) {
T[] s;
s.length = len;
int i;
int k;
while (i<len) {
s[i] = self.nextInCycle(k);
if (s[k] > 1) {
repeat(s[k] - 1,
(int j) {
if (++i == len) return;
s[i] = s[i-1];
}
);
}
if (++i == len) return s;
k++;
}
return s;
}
 
bool possibleKolakoski(T)(T[] self) {
auto len = self.length;
T[] rle;
auto prev = self[0];
int count = 1;
foreach (i; 1..len) {
if (self[i] == prev) {
count++;
} else {
rle ~= count;
count = 1;
prev = self[i];
}
}
// no point adding final 'count' to rle as we're not going to compare it anyway
foreach (i; 0..rle.length) {
if (rle[i] != self[i]) {
return false;
}
}
return true;
}
 
void main() {
auto ias = [[1,2],[2,1],[1,3,1,2],[1,3,2,1]];
auto lens = [20,20,30,30];
 
foreach (i,ia; ias) {
auto len = lens[i];
auto kol = ia.kolakoski(len);
writeln("First ", len, " members of the sequence generated by ", ia, ":");
writeln(kol);
write("Possible Kolakoski sequence? ");
if (kol.possibleKolakoski) {
writeln("Yes");
} else {
writeln("no");
}
writeln;
}
}</lang>
{{out}}
<pre>First 20 members of the sequence generated by [1, 2]:
[1, 2, 2, 1, 1, 2, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1]
Possible Kolakoski sequence? Yes
 
First 20 members of the sequence generated by [2, 1]:
[2, 2, 1, 1, 2, 1, 2, 2, 1, 2, 2, 1, 1, 2, 1, 1, 2, 2, 1, 2]
Possible Kolakoski sequence? Yes
 
First 30 members of the sequence generated by [1, 3, 1, 2]:
[1, 3, 3, 3, 1, 1, 1, 2, 2, 2, 1, 3, 1, 2, 2, 1, 1, 3, 3, 1, 2, 2, 2, 1, 3, 3, 1, 1, 2, 1]
Possible Kolakoski sequence? Yes
 
First 30 members of the sequence generated by [1, 3, 2, 1]:
[1, 3, 3, 3, 2, 2, 2, 1, 1, 1, 1, 1, 3, 3, 2, 2, 1, 1, 3, 2, 1, 1, 1, 1, 3, 3, 3, 2, 2, 1]
Possible Kolakoski sequence? no</pre>
 
=={{header|Go}}==
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