Data commit

Task/Bell-numbers/D/bell-numbers.d

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+import std.array : uninitializedArray;
+import std.bigint;
+import std.stdio : writeln, writefln;
+
+auto bellTriangle(int n) {
+    auto tri = uninitializedArray!(BigInt[][])(n);
+    foreach (i; 0..n) {
+        tri[i] = uninitializedArray!(BigInt[])(i);
+        tri[i][] = BigInt(0);
+    }
+    tri[1][0] = 1;
+    foreach (i; 2..n) {
+        tri[i][0] = tri[i - 1][i - 2];
+        foreach (j; 1..i) {
+            tri[i][j] = tri[i][j - 1] + tri[i - 1][j - 1];
+        }
+    }
+    return tri;
+}
+
+void main() {
+    auto bt = bellTriangle(51);
+    writeln("First fifteen and fiftieth Bell numbers:");
+    foreach (i; 1..16) {
+        writefln("%2d: %d", i, bt[i][0]);
+    }
+    writeln("50: ", bt[50][0]);
+    writeln;
+    writeln("The first ten rows of Bell's triangle:");
+    foreach (i; 1..11) {
+        writeln(bt[i]);
+    }
+}