1 files changed, 45 insertions, 0 deletions
diff --git a/euler27.c b/euler27.c
new file mode 100644
index 0000000..f2c2435
--- /dev/null
+++ b/euler27.c
@@ -0,0 +1,45 @@
+#include <stdio.h>
+#include <stdlib.h>
+#define MAX 3000000
+
+int notPrime[MAX]={0};
+
+void genprimes(int n)
+{
+	notPrime[0]=1;
+	notPrime[1]=1;
+	int i,j;
+	for (i=2;i<=n;++i){
+		if (!notPrime[i]){
+			for (j=i*2;j<=n;j+=i){
+				notPrime[j]=1;
+			}
+		}
+	}
+}
+	
+int main()
+{
+	int a,b,n;
+	int product=0,longest=0;
+	genprimes(MAX);
+	for (a=-999;a<=999;a+=2){
+		for (b=-997;b<=997;b+=2){
+			if (notPrime[abs(b)])
+				continue;
+			for (n=0;;++n){
+				int t=(n+a)*n+b;
+				if (notPrime[abs(t)]){
+					if (n>longest){
+						longest = n;
+						product = a*b;
+					}
+					break;
+				}
+			}
+		}
+	}
+	printf("%d\n",product);
+	return 0;
+}
+