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Pascal's triangle: Difference between revisions
Updated second and third D entries
(Updated second and third D entries) |
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=={{header|D}}==
===Less functional Version===
<lang d>int[][] pascalsTriangle(in int rows) pure nothrow {
auto tri = new int[][rows];
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[1, 9, 36, 84, 126, 126, 84, 36, 9, 1]]);
}</lang>
===More functional Version===
<lang d>import std.stdio, std.algorithm, std.range;
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auto p = [[1]];
foreach (_; 1 .. n)
p ~=
return p;
}
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Output:
<pre>[[1], [1, 1], [1, 2, 1], [1, 3, 3, 1], [1, 4, 6, 4, 1]]</pre>
===Alternative Version===
There is similarity between Pascal's triangle and [[Sierpinski triangle]]. Their difference are the initial line and the operation that act on the line element to produce next line. The following is a generic pascal's triangle implementation for positive number of lines output (n).
<lang d>import std.stdio, std.string, std.
string Pascal(alias dg, T, T initValue)(int n) {
string output;
void append(T[] l) {▼
output ~= format("%4s", format("%4s", e));
}▼
▲ }
foreach (int j; 1 .. lines[i-1].length)
lines[i][j] = dg(lines[i-1][j], lines[i-1][j-1]);
}
}
return output;
▲ return output;
}
string delegate(int n)
mixin Pascal!(dg, T, initValue);
return &Pascal;
}
char xor(char a, char b) { return a == b ? '_' : '*'; }▼
void main() {
auto pascal =
▲ static char xor(char a, char b) { return a == b ? '_' : '*'; }
auto sierpinski =
foreach (i; [1, 5, 9])
writef(pascal(i));
//
// Pascal triangle with xor operation
foreach(i; [16]) writef(sierpinski(i));▼
foreach (i; [16])
}</lang>
{{out}}
<pre> 1
1
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