init

problems/p19/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "p19"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+chrono = "0.4.41"

problems/p19/src/main.rs

@@ -0,0 +1,19 @@
+use chrono::{Datelike, NaiveDate, Weekday};
+
+fn main() {
+    let mut sum = 0;
+    for year in 1901..=2000 {
+        for month in 1..=12 {
+            let date = NaiveDate::from_ymd_opt(year, month, 1).unwrap();
+
+            // 获取星期几
+            let weekday = date.weekday();
+
+            // 判断是否为特定星期
+            if weekday == Weekday::Sun {
+                sum += 1;
+            }
+        }
+    }
+    println!("{sum}")
+}