longest-unique-substring.go

package main

import (
  "fmt"
  "strings"
)

func main() {
  var str string

  // Print our request to the user
  fmt.Println("Enter string to search?")

  // Request an number from the user and store it
  // in the nth variable
  fmt.Scanf("%s", &str)

  // Define variables to store the longest known string
  // and the current test string
  var longestString string = ""
  var currentString string = ""

  // Loop through each of the characters in the string
  for i := 0; i < len(str); i++ {
    // Get the next character
    var char string = string(str[i])

    // Check to see if the current test string contains
    // the next character
    if strings.Contains(currentString, char) {

      // See if the string we have finished
      // finding is the longest string
      if currentString > longestString {
        longestString = currentString
      }

      // Split the string on the repeated character
      currentString = strings.Split(currentString, char)[1]
    }

    // Add the next character to our current string
    currentString = currentString + char
  }

  // Output the longest string
  fmt.Println("The longest string is:")

  if len(currentString) > len(longestString) {
    fmt.Println(currentString)
  } else {
    fmt.Println(longestString)
  }
}