Add an example for ABC162-C

qryxip · qryxip · commit f1631ca797bf · 2020-05-19T00:20:10.000+09:00
diff --git a/examples/abc162-c.rs b/examples/abc162-c.rs
@@ -0,0 +1,29 @@
+// https://atcoder.jp/contests/abc162/tasks/abc162_c
+//
+// 以下のクレートを使用。
+// - `num`
+//     - `num-integer`
+// - `itertools`
+// - `proconio`
+
+use itertools::iproduct;
+use proconio::input;
+
+fn main() {
+    // `proconio::input!`。
+    //
+    // https://docs.rs/proconio/0.3.6/proconio/macro.input.html
+    input! {
+        k: u64,
+    }
+
+    // 三重ループを表わすイテレータを`itertools::iproduct!`で生み出す。
+    // GCDは`num_integer::gcd`で`fold`することで求められる。
+    //
+    // https://docs.rs/itertools/0.9/itertools/macro.iproduct.html
+    // https://docs.rs/num-integer/0.1/num_integer/fn.gcd.html
+    let ans = iproduct!(1..=k, 1..=k, 1..=k)
+        .map(|(a, b, c)| [a, b, c].iter().copied().fold(0, num::integer::gcd))
+        .sum::<u64>();
+    println!("{}", ans);
+}
diff --git a/test-examples.toml b/test-examples.toml
@@ -226,6 +226,13 @@ url = "https://atcoder.jp/contests/abc160/tasks/abc160_e"
 matching = "Words"
 meta = { using = ["itertools", "proconio"] }
 
+[examples.abc162-c]
+type = "Normal"
+name = "ABC162 - C - Sum of gcd of Tuples (Easy)"
+url = "https://atcoder.jp/contests/abc162/tasks/abc162_c"
+matching = "Words"
+meta = { using = ["itertools", "num", "proconio"] }
+
 [examples.agc020-c]
 type = "Normal"
 name = "AGC020: C - Median Sum"
