add initial data

0006-zigzag-conversion/src/main.rs

@@ -0,0 +1,53 @@
+fn main() {
+    println!("Hello, world!");
+}
+
+pub fn convert(s: String, num_rows: i32) -> String {
+    let bytes = s.as_bytes();
+    let mut result = vec![vec![]; num_rows as usize];
+
+    for (idx, byte) in bytes.iter().enumerate() {
+        let row = if num_rows == 1 {
+            0
+        } else {
+            let cycle_pos = idx % (2 * (num_rows - 1)) as usize;
+            if cycle_pos < num_rows as usize - 1 {
+                cycle_pos
+            } else {
+                2 * (num_rows as usize - 1) - cycle_pos
+            }
+        };
+
+        result[row].push(*byte);
+    }
+
+    result.into_iter().flatten().map(|b| b as char).collect()
+}
+
+#[cfg(test)]
+mod tests {
+    use super::convert;
+
+    #[test]
+    fn test_1() {
+        assert_eq!(
+            convert("PAYPALISHIRING".to_string(), 3),
+            "PAHNAPLSIIGYIR".to_string()
+        );
+    }
+    #[test]
+    fn test_2() {
+        assert_eq!(
+            convert("PAYPALISHIRING".to_string(), 4),
+            "PINALSIGYAHRPI".to_string()
+        );
+    }
+    #[test]
+    fn test_3() {
+        assert_eq!(convert("A".to_string(), 1), "A".to_string());
+    }
+    #[test]
+    fn test_4() {
+        assert_eq!(convert("AB".to_string(), 1), "AB".to_string());
+    }
+}