811-SubdomainVisitCount.go

package main

// 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, 10^4].
//     d1i, d2i, and d3i consist of lowercase English letters.

import "fmt"
import "strconv"

func subdomainVisits(cpdomains []string) []string {
    res, mp, n, s  := []string{}, make(map[string]int), 0, ""
    for _, domain := range cpdomains {
        for i, v := range domain {
            if v == ' ' { // "9001 discuss.leetcode.com" 分开 计数 域名 
                n, _ = strconv.Atoi(domain[:i])
                s = domain[i+1:]
            }
        }
        mp[s] += n // 整域名
        for i, v := range s {
            ts := ""
            if v == '.' { // 分解域名 
                ts = s[i+1:]
                mp[ts] += n
            }
        }
    }
    for k, v := range mp {
        res = append(res, strconv.Itoa(v) + " " + k)
    }
    return res
}

func main() {
    // 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.
    fmt.Println(subdomainVisits([]string{"9001 discuss.leetcode.com"})) // ["9001 leetcode.com","9001 discuss.leetcode.com","9001 com"]
    // 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.
    fmt.Println(subdomainVisits([]string{"900 google.mail.com", "50 yahoo.com", "1 intel.mail.com", "5 wiki.org"})) // ["901 mail.com","50 yahoo.com","900 google.mail.com","5 wiki.org","5 org","1 intel.mail.com","951 com"]
}