more solutions

1 files changed, 16 insertions, 3 deletions

diff --git a/20/solution.c b/20/solution.c
index cf61687..73beb80 100644
--- a/20/solution.c
+++ b/20/solution.c
@@ -16,9 +16,8 @@ long part1(long input)
 	long *houses = emalloc(sizeof(long) * input / 10);
 	#pragma omp parallel for
 	for (long i = 1; i < input / 10; i++)
-		for (long j = i; j < input / 10; j++)
+		for (long j = i; j < input / 10; j += i)
 			houses[j] += i * 10;
-	puts("filled houses");
 	for (long i = 1; i < input / 10; i++) {
 		if (houses[i] >= input) {
 			res = i;
@@ -31,11 +30,25 @@ long part1(long input)
 
 long part2(long input)
 {
-	return -1;
+	long res = -1;
+	long *houses = emalloc(sizeof(long) * input / 10);
+	#pragma omp parallel for
+	for (long i = 1; i < input / 10; i++)
+		for (long j = i, k = 0; j < input / 10 && k < 50; j += i, k++)
+			houses[j] += i * 11;
+	for (long i = 1; i < input / 10; i++) {
+		if (houses[i] >= input) {
+			res = i;
+			break;
+		}
+	}
+	free(houses);
+	return res;
 }
 
 int main(void)
 {
 	long input = 33100000;
 	printf("%ld\n", part1(input));
+	printf("%ld\n", part2(input));
 }