gistfile1.txt

package main

import (
	"fmt"
)

func displayDiff(oldVersion string, newVersion string) string {
	fmt.Println(oldVersion, newVersion)
	var f = [35][35]int{}
	var ni = [35][35]int{}
	var nj = [35][35]int{}

	var update = func(i, j, ii, jj, v int) {
		f[i][j] = v
		ni[i][j] = ii
		nj[i][j] = jj
	}

	var calc func(i, j int, os, ns string) int

	calc = func(i, j int, os, ns string) int {
		if f[i][j] != 0 {
			return f[i][j]
		}

		if i == len(os) && j == len(ns) {
			f[i][j] = 0
		} else if i == len(os) {
			f[i][j] = len(ns) - j
		} else if j == len(ns) {
			f[i][j] = len(os) - i
		} else if os[i] == ns[j] {
			f[i][j] = calc(i+1, j+1, os, ns) + 1
		} else {
			v := calc(len(os), j, os, ns) + len(os) - i
			update(i, j, len(os), j, v)

			if x := calc(i, len(ns), os, ns) + len(ns) - j; x < f[i][j] {
				update(i, j, i, len(ns), x)
			}

			for k := len(os); k > i; k-- {
				pf := calc(k, j, os, ns) + k - i
				if pf < f[i][j] {
					update(i, j, k, j, pf)
				}
			}

			for k := len(ns); k > j; k-- {
				pf := calc(i, k, os, ns) + k - j
				if pf < f[i][j] {
					update(i, j, i, k, pf)
				}
			}
		}

		return f[i][j]
	}

	var solution func(i, j int, os, ns string) string

	solution = func(i, j int, os, ns string) string {
		if i == len(os) && j == len(ns) {
			return ""
		} else if i == len(os) {
			return "[" + ns[j:] + "]"
		} else if j == len(ns) {
			return "(" + os[i:] + ")"
		} else if os[i] == ns[j] {
			return os[i:i+1] + solution(i+1, j+1, os, ns)
		} else {
			if ni[i][j] == i {
				return "[" + ns[j:nj[i][j]] + "]" + solution(i, nj[i][j], os, ns)
			} else {
				return "(" + os[i:ni[i][j]] + ")" + solution(ni[i][j], j, os, ns)
			}
		}
	}

	calc(0, 0, oldVersion, newVersion)
	return solution(0, 0, oldVersion, newVersion)
}

func main() {

	fmt.Println(displayDiff("_1233", "231233"))
}