题解 | 合并表记录

n_records = int(input())

res_dic = {}
for i in range(n_records):
    key, value = map(int, input().split())
    if key not in res_dic:
        res_dic[key] = value
    else:
        res_dic[key] += value

res_dict_sorted = dict(sorted(res_dic.items(), key=lambda x: x[0]))

for key, value in res_dict_sorted.items():
    print(f"{key} {value}")

#for index in sorted(res_dic):
#    print(f"{index} {res_dic[index]}")