Code RoomPivot marks to wide format
MediumPrep Room Coding #5033

Pivot marks to wide format

CodingAlgorithms & data structuresMid–Senior~10 min

Given `marks` with columns `student`, `subject` and `score`, reshape it so each student has one row and each subject is its own column. Return `student`, `math` and `science`, sorted by `student` ascending.

Implement
wide_marks(marks: dataframe) → dataframe
Examples
in[{"__df__":[{"score":88,"student":"ana","subject":"math"},{"score":92,"student":"ana","subject":"science"},{"score":75,"student":"ben","subject":"math"},{"score":64,"student":"ben","subject":"science"},{"score":95,"student":"cara","subject":"math"},{"score":81,"student":"cara","subject":"science"}]}]out[{"math":88,"science":92,"student":"ana"},{"math":75,"science":64,"student":"ben"},{"math":95,"science":81,"student":"cara"}]
What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

0:00 of about 10 min
InputExpectedGot
[{"__df__":[{"score":88,"student":"ana","subject":"math"},{"score":92,"student":"ana","subject":"science"},{"score":75,"student":"ben","subject":"math"},{"score":64,"student":"ben","subject":"science"},{"score":95,"student":"cara","subject":"math"},{"score":81,"student":"cara","subject":"science"}]}][{"math":88,"science":92,"student":"ana"},{"math":75,"science":64,"student":"ben"},{"math":95,"science":81,"student":"cara"}]not run yetsample