Overview

A string and a dictionary of words are given. The objective is to find the longest word in the dictionarywhich is present as a subsequence in the given string. If the number of possible results is more than 1 then return the longest word with the smallest lexicographical order.

Example 1

s = "mbacnago", dictionary = ["ale","mango","monkey","plea"]
Output: "mango"

Example 2

s = "mbacnago", dictionary = ["ba","ag"]
Output: "ag"

Program

Below is the program for the same

package main
import (
"fmt"
"sort"
)
func findLongestWord(s string, dictionary []string) string {
sort.Slice(dictionary, func(i, j int) bool {
lenI := len(dictionary[i])
lenJ := len(dictionary[j])
if lenI == lenJ {
return dictionary[i] < dictionary[j]
}
return lenI > lenJ
})
lenS := len(s)
for i := 0; i < len(dictionary); i++ {
if isSubstring(s, dictionary[i], lenS) {
return dictionary[i]
}
}
return ""
}
func isSubstring(s string, sub string, lenS int) bool {
lenSub := len(sub)
if lenSub == 0 {
return true
}
if lenSub > lenS {
return false
}
for i, j := 0, 0; i < lenS && j < lenSub; {
if i+lenSub-j-1 >= lenS {
return false
}
if s[i] == sub[j] {
j++
}
if j == lenSub {
return true
}
i++
}
return false
}
func main() {
output := findLongestWord("mbacnago", []string{"ale", "mango", "monkey", "plea"})
fmt.Println(output)
output = findLongestWord("mbacnago", []string{"ba", "ag"})
fmt.Println(output)
}

Output

mango
ag

Note: Check out our Golang Advanced Tutorial. The tutorials in this series are elaborative and we have tried to cover all concepts with examples. This tutorial is for those who are looking to gain expertise and a solid understanding of golang – Golang Advance Tutorial

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