solution for project euler problem 92

1 files changed, 45 insertions, 0 deletions

diff --git a/src/projecteuler/092.c b/src/projecteuler/092.c
new file mode 100644
index 0000000..8616cf8
--- /dev/null
+++ b/src/projecteuler/092.c
@@ -0,0 +1,45 @@
+
+
+const int limit = 10000000;
+
+const int squares[10] = { 0, 1, 4, 9, 16, 25, 36, 49, 64, 81 };
+
+int next_chain(int number)
+{
+	int sum = 0;
+	int digit;
+	while(number > 0)
+	{
+		digit = number % 10;
+		number = number / 10;
+		sum += squares[digit];
+	}
+	return sum;
+}
+
+int main()
+{
+	int* numbers = calloc(limit, sizeof(int));
+	int i, count;
+
+	for(i=0; i<limit; i++)
+		numbers[i] = next_chain(i);
+
+	count = 0;
+
+	for(i=1; i<limit; i++)
+	{
+		int next = numbers[i];
+		while(next != 1 && next != 89)
+			next = numbers[next];
+
+		numbers[i] = next;
+		if(next == 89)
+			count++;
+	}
+
+	printf("%d\n", count);
+
+	return 0;
+}
+