feat(345): completed both challenges

2 files changed, 52 insertions, 0 deletions

diff --git a/challenge-345/benjamin-andre/rust/ch-1.rs b/challenge-345/benjamin-andre/rust/ch-1.rs
new file mode 100755
index 0000000000..e5d7fb1416
--- /dev/null
+++ b/challenge-345/benjamin-andre/rust/ch-1.rs
@@ -0,0 +1,21 @@
+#!/bin/sh
+//usr/bin/env rustc --test $0 -o kachow && ./kachow --nocapture; rm -f kachow ; exit
+
+fn peak_positions(ints: &[i32]) -> Vec<usize> {
+    (0..ints.len())
+        .filter(|&i| {
+            let left_ok = i == 0 || ints[i] > ints[i - 1];
+            let right_ok = i == ints.len() - 1 || ints[i] > ints[i + 1];
+            left_ok && right_ok && !(i == 0 && i == ints.len() - 1)
+        })
+        .collect()
+}
+
+#[test]
+fn example() {
+    assert_eq!(peak_positions(&[1, 3, 2]), vec![1]);
+    assert_eq!(peak_positions(&[2, 4, 6, 5, 3]), vec![2]);
+    assert_eq!(peak_positions(&[1, 2, 3, 2, 4, 1]), vec![2, 4]);
+    assert_eq!(peak_positions(&[5, 3, 1]), vec![0]);
+    assert_eq!(peak_positions(&[1, 5, 1, 5, 1, 5, 1]), vec![1, 3, 5]);
+}
diff --git a/challenge-345/benjamin-andre/rust/ch-2.rs b/challenge-345/benjamin-andre/rust/ch-2.rs
new file mode 100755
index 0000000000..002414605f
--- /dev/null
+++ b/challenge-345/benjamin-andre/rust/ch-2.rs
@@ -0,0 +1,31 @@
+#!/bin/sh
+//usr/bin/env rustc --test $0 -o kachow && ./kachow --nocapture; rm -f kachow ; exit
+
+fn last_visitor(ints: &[i32]) -> Vec<i32> {
+    let mut seen = Vec::new();
+    let mut ans = Vec::new();
+    let mut neg_count = 0;
+    for &n in ints {
+        if n > 0 {
+            seen.insert(0, n);
+            neg_count = 0;
+        } else {
+            if neg_count < seen.len() {
+                ans.push(seen[neg_count]);
+            } else {
+                ans.push(-1);
+            }
+            neg_count += 1;
+        }
+    }
+    ans
+}
+
+#[test]
+fn example() {
+    assert_eq!(last_visitor(&[5, -1, -1]), vec![5, -1]);
+    assert_eq!(last_visitor(&[3, 7, -1, -1, -1]), vec![7, 3, -1]);
+    assert_eq!(last_visitor(&[2, -1, 4, -1, -1]), vec![2, 4, 2]);
+    assert_eq!(last_visitor(&[10, 20, -1, 30, -1, -1]), vec![20, 30, 20]);
+    assert_eq!(last_visitor(&[-1, -1, 5, -1]), vec![-1, -1, 5]);
+}