Added solution for 2640

Author: chirag64

02640. Find the Score of All Prefixes of an Array.rs

@@ -0,0 +1,18 @@
+use std::cmp::max;
+
+impl Solution {
+    // Keep track of highest num and sum of score instead of calculating score vector everytime. For every iteration of nums, add previous score to highest_num and current num
+    pub fn find_prefix_score(nums: Vec<i32>) -> Vec<i64> {
+        let mut ans:Vec<i64> = Vec::new();
+        let mut highest_num = 0;
+        let mut score = 0;
+        
+        for num in nums {
+            highest_num = max(highest_num, num as i64);
+            score += (highest_num + num as i64);
+            ans.push(score);
+        }
+        
+        return ans;
+    }
+}