making-file-names-unique.go

// Given an array of strings names of size n. You will create n folders in your file system such that, at the ith minute, you will create a folder with the name names[i].
//
// Since two files cannot have the same name, if you enter a folder name that was previously used, the system will have a suffix addition to its name in the form of (k), where, k is the smallest positive integer such that the obtained name remains unique.
//
// Return an array of strings of length n where ans[i] is the actual name the system will assign to the ith folder when you create it.
//
//  
// Example 1:
//
//
// Input: names = ["pes","fifa","gta","pes(2019)"]
// Output: ["pes","fifa","gta","pes(2019)"]
// Explanation: Let's see how the file system creates folder names:
// "pes" --> not assigned before, remains "pes"
// "fifa" --> not assigned before, remains "fifa"
// "gta" --> not assigned before, remains "gta"
// "pes(2019)" --> not assigned before, remains "pes(2019)"
//
//
// Example 2:
//
//
// Input: names = ["gta","gta(1)","gta","avalon"]
// Output: ["gta","gta(1)","gta(2)","avalon"]
// Explanation: Let's see how the file system creates folder names:
// "gta" --> not assigned before, remains "gta"
// "gta(1)" --> not assigned before, remains "gta(1)"
// "gta" --> the name is reserved, system adds (k), since "gta(1)" is also reserved, systems put k = 2. it becomes "gta(2)"
// "avalon" --> not assigned before, remains "avalon"
//
//
// Example 3:
//
//
// Input: names = ["onepiece","onepiece(1)","onepiece(2)","onepiece(3)","onepiece"]
// Output: ["onepiece","onepiece(1)","onepiece(2)","onepiece(3)","onepiece(4)"]
// Explanation: When the last folder is created, the smallest positive valid k is 4, and it becomes "onepiece(4)".
//
//
//  
// Constraints:
//
//
// 	1 <= names.length <= 5 * 104
// 	1 <= names[i].length <= 20
// 	names[i] consists of lowercase English letters, digits, and/or round brackets.
//
//


func getFolderNames(names []string) []string {
    m := make(map[string]int)
    sl := []string{}
    for _, name := range names {
        if _, found := m[name]; !found {
            sl = append(sl, name)
            m[name]++
        } else {
            k := m[name]
            next := name + fmt.Sprintf("(%d)", k)
            for {
                if _, exists := m[next]; exists {
                    k++
                    next = name + fmt.Sprintf("(%d)", k)
                    continue
                }
                break
            }
            m[name] = k
            m[next]++
            sl = append(sl, next)
        }
    }
    return sl
}