Various bug fixes

CSClasses/Algorithms.cs

@@ -32,7 +32,18 @@ namespace mee{
 		//These are a few functions that help with some utility within the class
 		//Returns the sqrt of the BigInt passed to it
 		public static BigInteger BigIntegerSqrt(BigInteger num){
-			return (BigInteger)Math.Ceiling(Math.Exp(BigInteger.Log(num) / 2));
+			BigInteger sqrt;
+
+			//Get the sqrt from the general formula
+			double tempSqrt = Math.Exp(BigInteger.Log(num) / 2);
+			//Account for floating-point rounding errors
+			if((BigInteger)(tempSqrt * tempSqrt) < num){
+				sqrt = (BigInteger)Math.Ceiling(tempSqrt);
+			}
+			else{
+				sqrt = (BigInteger)tempSqrt;
+			}
+			return sqrt;
 		}
 
 		//These functions return a list of all Fibonacci numbers <= goalNumber
@@ -557,7 +568,7 @@ namespace mee{
 			}
 
 			//Start at 3 and loop through all numbers < sqrt(goalNumber) looking for a number that divides it evenly
-			double topPossibleDivisor = Math.Exp(BigInteger.Log(goalNumber) / 2);
+			double topPossibleDivisor = (double)BigIntegerSqrt(goalNumber);
 			for(long possibleDivisor = 1;possibleDivisor <= topPossibleDivisor;++possibleDivisor){
 				//If you find one add it and the number it creates to the list
 				if((goalNumber % possibleDivisor) == 0){
@@ -593,21 +604,36 @@ namespace mee{
 			return sum;
 		}
 		public static int GetProd(List<int> ary){
-			int prod = 1;
+			//If a blank list was passed to the function return 0 as the product
+			if(ary.Capacity == 0){
+				return 0;
+			}
+
+			int prod = 1;	//Start at 1 because x * 1 = x
 			foreach(int num in ary){
 				prod *= num;
 			}
 			return prod;
 		}
 		public static long GetProd(List<long> ary){
-			long prod = 1;
+			//If a blank list was passed to the function return 0 as the product
+			if(ary.Capacity == 0){
+				return 0;
+			}
+
+			long prod = 1;	//Start at 1 because x * 1 = x
 			foreach(long num in ary){
 				prod *= num;
 			}
 			return prod;
 		}
 		public static BigInteger GetProd(List<BigInteger> ary){
-			BigInteger prod = 1;
+			//If a blank list was passed to the function return 0 as the product
+			if(ary.Capacity == 0){
+				return 0;
+			}
+
+			BigInteger prod = 1;	//Start at 1 because x * 1 = x
 			foreach(BigInteger num in ary){
 				prod *= num;
 			}