Create highest-grade-for-each-student.sql

Author: kamyu104

MySQL/highest-grade-for-each-student.sql

@@ -0,0 +1,14 @@
+# Time:  O(nlogn)
+# Space: O(n)
+
+SELECT student_id, 
+       Min(course_id) AS course_id, 
+       grade 
+FROM   enrollments 
+WHERE  ( student_id, grade ) IN (SELECT student_id, 
+                                        Max(grade) 
+                                 FROM   enrollments 
+                                 GROUP  BY student_id 
+                                 ORDER  BY NULL) 
+GROUP  BY student_id 
+ORDER  BY student_id