题解 | #合并表记录#

对字典的索引和修改是关键，注意排序时按key值排序，最后输出的格式要注意。

num1 = int(input())

dict1 = {}

for i in range(num1):
    index,value = [int(x) for x in input().split()]

    k = 0
    for key in dict1:
        if index == key:
            dict1[index] += value
            k = 1
    if k == 0:
        dict1[index] = value

dict2 = sorted(dict1.items(), key = lambda x:x[0])

for key,value in dict2:
    print(key, value)