tasks a-s

Task/Pascals-triangle/JavaScript/pascals-triangle.js

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+// Pascal's triangle object
+function pascalTriangle (rows) {
+
+	// Number of rows the triangle contains
+	this.rows = rows;
+
+	// The 2D array holding the rows of the triangle
+	this.triangle = new Array();
+	for (var r = 0; r < rows; r++) {
+		this.triangle[r] = new Array();
+		for (var i = 0; i <= r; i++) {
+			if (i == 0 || i == r)
+				this.triangle[r][i] = 1;
+			else
+				this.triangle[r][i] = this.triangle[r-1][i-1]+this.triangle[r-1][i];
+		}
+	}
+
+	// Method to print the triangle
+	this.print = function(base) {
+		if (!base)
+			base = 10;
+
+		// Private method to calculate digits in number
+		var digits = function(n,b) {
+			var d = 0;
+			while (n >= 1) {
+				d++;
+				n /= b;
+			}
+			return d;
+		}
+
+		// Calculate max spaces needed
+		var spacing = digits(this.triangle[this.rows-1][Math.round(this.rows/2)],base);
+
+		// Private method to add spacing between numbers
+		var insertSpaces = function(s) {
+			var buf = "";
+			while (s > 0) {
+				s--;
+				buf += " ";
+			}
+			return buf;
+		}
+
+		// Print the triangle line by line
+		for (var r = 0; r < this.triangle.length; r++) {
+			var l = "";
+			for (var s = 0; s < Math.round(this.rows-1-r); s++) {
+				l += insertSpaces(spacing);
+			}
+			for (var i = 0; i < this.triangle[r].length; i++) {
+				if (i != 0)
+					l += insertSpaces(spacing-Math.ceil(digits(this.triangle[r][i],base)/2));
+				l += this.triangle[r][i].toString(base);
+				if (i < this.triangle[r].length-1)
+					l += insertSpaces(spacing-Math.floor(digits(this.triangle[r][i],base)/2));
+			}
+			print(l);
+		}
+	}
+
+}
+
+// Display 4 row triangle in base 10
+var tri = new pascalTriangle(4);
+tri.print();
+// Display 8 row triangle in base 16
+tri = new pascalTriangle(8);
+tri.print(16);