Weekly Challenge Blast from the Past

1 files changed, 64 insertions, 0 deletions

diff --git a/challenge-013/zapwai/rust/ch-1.rs b/challenge-013/zapwai/rust/ch-1.rs
new file mode 100644
index 0000000000..678d0c2954
--- /dev/null
+++ b/challenge-013/zapwai/rust/ch-1.rs
@@ -0,0 +1,64 @@
+fn is_leap_year (year :i32) -> bool {
+    if year % 400 == 0 {
+	return true;
+    }
+    if year % 100 == 0 {
+	return false;
+    }
+    if year % 4  == 0 {
+	return true;
+    }
+    return false;
+}
+
+fn days_to_date(mut days :i32, year :i32) -> String {
+    if days > 365 {
+	return "erroneous number of days\n".to_string();
+    }
+    days += 1;
+    let mut d = vec![31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31];
+    if is_leap_year(year) {
+	d[1] += 1;
+    }
+    let mut month = 0;
+    while days > d[month] {
+	days -= d[month];
+	month += 1;    
+    }
+    month += 1;
+    return format!("{:02}-{:02}-{}", month, days, year);
+}
+
+fn fridays(year :i32) {
+    let day = vec![ "sat", "sun", "mon", "tue", "wed", "thu", "fri" ];
+    let base_year = 2000;
+    let mut skip_days = year - base_year;
+    for yr in base_year .. year {
+	if is_leap_year(yr) {
+	    skip_days += 1;
+	}
+    }
+    let mut first_fri_delta = 0;
+    while "fri" != day[((skip_days + first_fri_delta)%7) as usize] {
+	first_fri_delta += 1;
+    }
+    let mut n = first_fri_delta;
+    let mut last_fridays :Vec<String> = Vec::new();
+    let mut tmp = String::from("01-01-1900");
+    while n < 365 {
+	let date = days_to_date(n, year).to_string();
+	if &tmp[0..2] != &date[0..2] {
+	    last_fridays.push(tmp);
+	}
+	n += 7;
+	tmp = date;
+    }
+    last_fridays.push(tmp);
+    for w in last_fridays {
+	println!("{w}");
+    }
+}
+
+fn main() {
+    fridays(2024);
+}