## Algorithm

Problem Name: 811. Subdomain Visit Count

A website domain `"discuss.leetcode.com"` consists of various subdomains. At the top level, we have `"com"`, at the next level, we have `"leetcode.com"` and at the lowest level, `"discuss.leetcode.com"`. When we visit a domain like `"discuss.leetcode.com"`, we will also visit the parent domains `"leetcode.com"` and `"com"` implicitly.

A count-paired domain is a domain that has one of the two formats `"rep d1.d2.d3"` or `"rep d1.d2"` where `rep` is the number of visits to the domain and `d1.d2.d3` is the domain itself.

• For example, `"9001 discuss.leetcode.com"` is a count-paired domain that indicates that `discuss.leetcode.com` was visited `9001` times.

Given an array of count-paired domains `cpdomains`, return an array of the count-paired domains of each subdomain in the input. You may return the answer in any order.

Example 1:

```Input: cpdomains = ["9001 discuss.leetcode.com"]
Output: ["9001 leetcode.com","9001 discuss.leetcode.com","9001 com"]
Explanation: We only have one website domain: "discuss.leetcode.com".
As discussed above, the subdomain "leetcode.com" and "com" will also be visited. So they will all be visited 9001 times.
```

Example 2:

```Input: cpdomains = ["900 google.mail.com", "50 yahoo.com", "1 intel.mail.com", "5 wiki.org"]
Output: ["901 mail.com","50 yahoo.com","900 google.mail.com","5 wiki.org","5 org","1 intel.mail.com","951 com"]
Explanation: We will visit "google.mail.com" 900 times, "yahoo.com" 50 times, "intel.mail.com" once and "wiki.org" 5 times.
For the subdomains, we will visit "mail.com" 900 + 1 = 901 times, "com" 900 + 50 + 1 = 951 times, and "org" 5 times.
```

Constraints:

• `1 <= cpdomain.length <= 100`
• `1 <= cpdomain[i].length <= 100`
• `cpdomain[i]` follows either the `"repi d1i.d2i.d3i"` format or the `"repi d1i.d2i"` format.
• `repi` is an integer in the range `[1, 104]`.
• `d1i`, `d2i`, and `d3i` consist of lowercase English letters.

## Code Examples

### #1 Code Example with Java Programming

```Code - Java Programming```

``````
class Solution {
public List subdomainVisits(String[] cpdomains) {
Map map = new HashMap<>();
for (String cpdomain : cpdomains) {
int spaceIdx = cpdomain.indexOf(' ');
int count = Integer.parseInt(cpdomain.substring(0, spaceIdx));
String[] subdomains = cpdomain.substring(spaceIdx + 1).split("\\.");
StringBuilder sb = new StringBuilder();
for (int i = subdomains.length - 1; i >= 0; i--) {
sb.insert(0, subdomains[i]);
String currDomain = sb.toString();
map.put(currDomain, map.getOrDefault(currDomain, 0L) + count);
sb.insert(0, ".");
}
}
List < String> result = new ArrayList<>();
for (String key : map.keySet()) {
result.add(map.get(key) + " " + key);
}
return result;
}
}
``````
Copy The Code &

Input

cmd
cpdomains = ["9001 discuss.leetcode.com"]

Output

cmd
["9001 leetcode.com","9001 discuss.leetcode.com","9001 com"]

### #2 Code Example with Python Programming

```Code - Python Programming```

``````
class Solution:
def subdomainVisits(self, cpdomains):
counter = collections.Counter()
for cpdomain in cpdomains:
count, *domains = cpdomain.replace(" ",".").split(".")
for i in range(len(domains)):
counter[".".join(domains[i:])] += int(count)
return [" ".join((str(v), k)) for k, v in counter.items()]
``````
Copy The Code &

Input

cmd
cpdomains = ["9001 discuss.leetcode.com"]

Output

cmd
["9001 leetcode.com","9001 discuss.leetcode.com","9001 com"]

### #3 Code Example with C# Programming

```Code - C# Programming```

``````
using System.Collections.Generic;

namespace LeetCode
{
public class _0811_SubdomainVisitCount
{
public IList < string> SubdomainVisits(string[] cpdomains)
{
var counts = new Dictionary();
foreach (var domain in cpdomains)
{
var cpinfo = domain.Split(' ');

int count = int.Parse(cpinfo[0]);

var frags = cpinfo[1].Split('.');
var currentDomain = "";
for (int i = frags.Length - 1; i >= 0; i--)
{
currentDomain = frags[i] + (i  <  frags.Length - 1 ? "." : "") + currentDomain;
if (counts.TryGetValue(currentDomain, out var existCount))
counts[currentDomain] = existCount + count;
else
counts[currentDomain] = count;
}
}

var answer = new List < string>();
foreach (var domain in counts.Keys)
}
}
}
``````
Copy The Code &

Input

cmd
cpdomains = ["900 google.mail.com", "50 yahoo.com", "1 intel.mail.com", "5 wiki.org"]

Output

cmd
["901 mail.com","50 yahoo.com","900 google.mail.com","5 wiki.org","5 org","1 intel.mail.com","951 com"]