Added Number of Segments in a String

Author: ryanoneill

src/lib.rs

@@ -394,7 +394,7 @@ pub mod longest_repeating_character_replacement; // 424 ✓
 // pub mod n_ary_tree_level_order_traversal; // 429 - This problem is unavailable in Rust
 
 pub mod minimum_genetic_mutation; // 433 ✓
-
+pub mod number_of_segments_in_a_string; // 434 ✓
 pub mod non_overlapping_intervals; // 435 ✓
 
 pub mod path_sum_iii; // 437 ✓

src/number_of_segments_in_a_string.rs

@@ -0,0 +1,66 @@
+/// Given a string `s`, return the number of segments in the string.
+///
+/// A segment is defined to be a contiguous sequence of non-space characters.
+struct Solution;
+
+impl Solution {
+
+    pub fn count_segments(s: String) -> i32 {
+        let mut result = 0;
+        let mut last_was_space = true;
+
+        for c in s.chars() {
+            match c {
+                ' ' => {
+                    if !last_was_space {
+                        result += 1;
+                        last_was_space = true;
+                    }
+                }
+                _ => {
+                    last_was_space = false;
+                }
+            }
+        }
+        if !last_was_space {
+            result += 1;
+        }
+        
+        result
+    }
+
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    #[test]
+    fn example_1() {
+        let s = str!("Hello, my name is John");
+        let result = Solution::count_segments(s);
+        assert_eq!(result, 5);
+    }
+
+    #[test]
+    fn example_2() {
+        let s = str!("Hello");
+        let result = Solution::count_segments(s);
+        assert_eq!(result, 1);
+    }
+
+    #[test]
+    fn example_3() {
+        let s = str!("");
+        let result = Solution::count_segments(s);
+        assert_eq!(result, 0);
+    }
+
+    #[test]
+    fn example_4() {
+        let s = str!("                ");
+        let result = Solution::count_segments(s);
+        assert_eq!(result, 0);
+    }
+
+}