Description

Data table records include table index index and numerical value (positive integer in the int range). Please merge the records with the same table index, that is, sum the values ​​of the same index, and output the output in ascending order of the index value.

Hint:
0 <= index <= 11111111
1 <= value <= 100000

Enter description:

First enter the number of key-value pairs n (1 <= n <= 500)
Next n lines enter paired index and value values ​​in each line, separated by spaces

Output description:

Output the merged key-value pair (multiple lines)

Example 1

Enter:

4
0 1
0 2
1 2
3 4

Output:

0 3
1 2
3 4

Analysis

1. Create an empty object to receive key-value pairs
2. Cut the incoming string by spaces and turn it into an array
3. Use k and v to store two items of data in the array respectively k = arr[0] v = arr[1]
4. Judging whether the key names of the arrays are the same, if they are the same, the values ​​are added, and if they are different, the corresponding v is stored

Code

let obj = {}while((str = readline())){const arr = str.split(' ')const k = +arr[0]const v = +arr[1]if(v) {// If the key name is repeated, the key value is addedif(obj[k]) {obj[k] += v} else {// If there is no same key name, store this key valueobj[k] = v}}}// Traverse the obj object and output the value of the key-value pairfor(key in obj) {console.log(key + ' ' + obj[key])}