任意の基準でソートして貪欲
C - Different Strokes
O(N)
import sys import math import heapq import itertools from collections import deque from functools import reduce # main def main(): N = int(input()) BA = [] for i in range(N): a, b = list(map(int, input().split())) BA.append([-a-b, a, b]) BA.sort() ans=0 for i in range(N): c, a, b = BA[i] if i%2 == 0: ans += a else: ans -= b print(ans) # エントリポイント if __name__ == '__main__': main()