Overview

This is a problem where you calculate each participant’s final score \(A_i + B_i\) and find the participant number with the maximum value.

Analysis

• Since the final score is simply \(A_i + B_i\), you just need to compute the total score for everyone and find the “maximum value.”
• It is guaranteed that “there is exactly one person with the highest score,” so there is no need to handle ties (dealing with multiple candidates).
• You could naively store all \(A_i, B_i\) in arrays and then find the maximum in \(O(N)\), but updating the maximum while reading without storing is simpler and saves memory.
• Since \(N \le 2 \times 10^5\), processing one iteration at a time in a loop is the most reliable approach (brute force is sufficiently fast).

Example: - Participant 1: \(A_1=30, B_1=40 \Rightarrow 70\) - Participant 2: \(A_2=50, B_2=10 \Rightarrow 60\) - Participant 3: \(A_3=20, B_3=80 \Rightarrow 100\)
The maximum is 100, so the answer is 3.

Algorithm

1. Prepare variables best_sum (the maximum total score so far) and best_idx (the corresponding participant number).
2. For \(i=1\) to \(N\), read \((A_i, B_i)\) in order and compute \(s = A_i + B_i\).
3. If \(s > best_sum\), update best_sum = s and best_idx = i.
4. After processing all participants, output best_idx.

Complexity

• Time complexity: \(O(N)\) (each participant is processed exactly once)
• Space complexity: \(O(1)\) (only the maximum value and its index are stored; the entire input is not saved in an array)

Implementation Notes

• Participant numbers are 1-indexed as stated in the problem, so writing the loop as for i in range(1, n + 1) helps avoid off-by-one errors.

• In Python, when the input is large, reading all at once with sys.stdin.buffer.read().split() is faster than repeatedly calling input() (the submitted code uses this approach).

  Source Code

import sys

def main():
    it = iter(sys.stdin.buffer.read().split())
    n = int(next(it))
    best_sum = -1
    best_idx = -1
    for i in range(1, n + 1):
        a = int(next(it))
        b = int(next(it))
        s = a + b
        if s > best_sum:
            best_sum = s
            best_idx = i
    print(best_idx)

if __name__ == "__main__":
    main()

This editorial was generated by gpt-5.2-high.