add: H-Index

Author: sidvishnoi

0274-h-index.rs

@@ -0,0 +1,36 @@
+struct Solution;
+
+impl Solution {
+    pub fn h_index(citations: Vec<i32>) -> i32 {
+        let n = citations.len();
+        let mut buckets = vec![0; n + 1];
+        for c in citations {
+            if c >= n as i32 {
+                buckets[n] += 1;
+            } else {
+                buckets[c as usize] += 1;
+            }
+        }
+
+        let mut total = 0;
+        for (i, count) in buckets.into_iter().enumerate().rev() {
+            total += count;
+            if total >= i as i32 {
+                return i as i32;
+            }
+        }
+        0
+    }
+}
+
+fn main() {
+    assert_eq!(3, Solution::h_index(vec![0, 3, 6, 1, 5]));
+    assert_eq!(3, Solution::h_index(vec![3, 3, 25, 8, 5]));
+    assert_eq!(2, Solution::h_index(vec![0, 5, 2, 6, 1]));
+    assert_eq!(1, Solution::h_index(vec![0, 1]));
+    assert_eq!(0, Solution::h_index(vec![0, 0]));
+    assert_eq!(1, Solution::h_index(vec![1, 1]));
+    assert_eq!(1, Solution::h_index(vec![1, 1, 1]));
+    assert_eq!(1, Solution::h_index(vec![100]));
+    assert_eq!(0, Solution::h_index(vec![]));
+}