Add References to git

info/Minesweeper2/MinesweeperSolver/PrimeSieve.cs

@@ -0,0 +1,129 @@
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Text;
+
+namespace MinesweeperSolver {
+
+    public class PrimeSieve {
+
+        // iterator for prime numbers
+        public class Primes : IEnumerable<int>, IEnumerator<int> {
+
+            private int index = 0;
+            private readonly int stop;
+            private int nextPrime;
+            private readonly bool[] composite;
+
+
+            public int Current => Next();
+
+            object IEnumerator.Current => Next();
+
+            public Primes(bool[] composite, int start, int stop) {
+                this.index = start;
+                this.stop = stop;
+                this.composite = composite;
+                this.nextPrime = findNext();
+            }
+
+            public int Next() {
+                int result = nextPrime;
+                nextPrime = findNext();
+
+                return result;
+            }
+
+            private int findNext() {
+
+                int next = -1;
+                while (index <= stop && next == -1) {
+                    if (!composite[index]) {
+                        next = index;
+                    }
+                    index++;
+                }
+
+                return next;
+
+            }
+
+            public void Dispose() {
+                
+            }
+
+            public bool MoveNext() {
+                return (nextPrime != -1);
+            }
+
+            public void Reset() {
+                throw new NotImplementedException();
+            }
+
+            public IEnumerator<int> GetEnumerator() {
+                return this;
+            }
+
+            IEnumerator IEnumerable.GetEnumerator() {
+                return this;
+            }
+        }
+
+
+        private readonly bool[] composite;
+	    private readonly int max;
+
+        public PrimeSieve(int n) {
+
+            if (n < 2) {
+                max = 2;
+            } else {
+                max = n;
+            }
+
+            composite = new bool[max + 1];
+
+            int rootN = (int)Math.Floor(Math.Sqrt(n));
+
+            for (int i = 2; i < rootN; i++) {
+
+                // if this is a prime number (not composite) then sieve the array
+                if (!composite[i]) {
+                    int index = i + i;
+                    while (index <= max) {
+                        composite[index] = true;
+                        index = index + i;
+                    }
+                }
+            }
+
+        }
+
+
+
+        public bool IsPrime(int n) {
+		    if (n <= 1 || n > max) {
+                throw new Exception("Test value " + n + " is out of range 2 - " + max);
+            }
+		
+		    return !composite [n];
+        }
+
+        public IEnumerable<int> getPrimesIterable(int start, int stop) {
+    	
+    	    if (start > stop) {
+                throw new Exception("start " + start + " must be <= to stop " + stop);
+            }
+		    if (start <= 1 || start > max) {
+                throw new Exception("Start value " + start + " is out of range 2 - " + max);
+            }
+		    if (stop <= 1 || stop > max) {
+                throw new Exception("Stop value " + stop + " is out of range 2 - " + max);
+            }
+    	
+    	    return new Primes(composite, start, stop);
+    }
+	
+}
+
+}