Problem
Each row of scores holds one student's test scores. Compute each student's average with a helper function and return the row index of the student with the highest average. If several tie, return the smallest index.
Implement top_student(scores).
Input
scores: One row of scores per student; every row has at least one score.
Output
Return the index of the top student.
Constraints
1 ≤ students ≤ 1,000; 1 ≤ scores per student ≤ 100; 0 ≤ score ≤ 100
Examples
Input:
scores = [
[80, 90],
[95, 85],
[70, 100]
]
Expected output:
expected = 1Input:
std::vector<std::vector<long long>> scores = {
{80, 90},
{95, 85},
{70, 100}
};
Expected output:
long long expected = 1;Input:
long[][] scores = new long[][] {
new long[] {80, 90},
new long[] {95, 85},
new long[] {70, 100}
};
Expected output:
long expected = 1;Explanation
Averages are 85, 90 and 85, so student 1 has the highest average.
Input:
scores = [
[60],
[60, 60]
]
Expected output:
expected = 0Input:
std::vector<std::vector<long long>> scores = {
{60},
{60, 60}
};
Expected output:
long long expected = 0;Input:
long[][] scores = new long[][] {
new long[] {60},
new long[] {60, 60}
};
Expected output:
long expected = 0;Explanation
Both averages are 60; the tie goes to the smaller index, 0.
How to approach it
Try on your own first, then open one hint at a time.
Hint 1
Compare students by their average score, not by a single test.
Hint 2
Compute each row’s average and keep the best index seen so far.
Hint 3
When averages tie, keep the earlier student instead of replacing it.
Expected complexity
O(total scores) time, O(1) extra space
References
This challenge is adapted for CodeUtility. Follow the statement and constraints above.