Data commit

Task/Long-year/C/long-year.c

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+#include <stdio.h>
+#include <math.h>
+
+// https://webspace.science.uu.nl/~gent0113/calendar/isocalendar.htm
+
+int p(int year) {
+	return (int)((double)year + floor(year/4) - floor(year/100) + floor(year/400)) % 7;
+}
+
+int is_long_year(int year) {
+	return p(year) == 4 || p(year - 1) == 3;
+}
+
+void print_long_years(int from, int to) {
+	for (int year = from; year <= to; ++year) {
+		if (is_long_year(year)) {
+			printf("%d ", year);
+		}
+	}
+}
+
+int main() {
+
+	printf("Long (53 week) years between 1800 and 2100\n\n");
+	print_long_years(1800, 2100);
+	printf("\n");
+	return 0;
+}