rs: add «169. Majority Element»

Signed-off-by: Matej Focko <me@mfocko.xyz>

rs/majority-element.rs

@@ -0,0 +1,44 @@
+use rand::distributions::{Distribution, Uniform};
+
+struct Solution {}
+impl Solution {
+    pub fn majority_element(mut nums: Vec<i32>) -> i32 {
+        let threshold = nums.len() >> 1;
+
+        let distribution = Uniform::new(0, nums.len());
+        let mut rng = rand::thread_rng();
+        loop {
+            let sample = nums[distribution.sample(&mut rng)];
+            println!("Picking sample: {}", sample);
+            if sample == i32::MIN {
+                continue;
+            }
+
+            let mut counter = 0;
+            for x in &mut nums {
+                if *x == sample {
+                    counter += 1;
+                    *x = i32::MIN;
+                }
+
+                if counter > threshold {
+                    return sample;
+                }
+            }
+        }
+    }
+}
+
+fn main() {
+    assert_eq!(Solution::majority_element(vec![3, 2, 3]), 3);
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_tle1() {
+        assert_eq!(Solution::majority_element(vec![3, 2, 3]), 3);
+    }
+}