From d36f1554da2bc0ee9f0e6e67e496445b2c0e5c53 Mon Sep 17 00:00:00 2001
From: Matej Focko <me@mfocko.xyz>
Date: Mon, 5 Aug 2024 00:03:44 +0200
Subject: [PATCH] =?UTF-8?q?go:=20add=20=C2=AB72.=20Edit=20Distance=C2=BB?=
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Signed-off-by: Matej Focko <me@mfocko.xyz>
---
 go/edit-distance.go | 60 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 60 insertions(+)
 create mode 100644 go/edit-distance.go

diff --git a/go/edit-distance.go b/go/edit-distance.go
new file mode 100644
index 0000000..65c1f20
--- /dev/null
+++ b/go/edit-distance.go
@@ -0,0 +1,60 @@
+package main
+
+const UNSET int = -1
+
+type Solver struct {
+	word1 string
+	word2 string
+	dp    [][]int
+}
+
+func makeSolver(word1, word2 string) Solver {
+	dp := make([][]int, len(word1))
+	for i := range len(word1) {
+		dp[i] = make([]int, len(word2))
+		for j := range len(word2) {
+			dp[i][j] = UNSET
+		}
+	}
+
+	return Solver{
+		word1: word1,
+		word2: word2,
+		dp:    dp,
+	}
+}
+
+func (s *Solver) solve(i, j int) int {
+	if i >= len(s.word1) {
+		return len(s.word2) - j
+	}
+
+	if j >= len(s.word2) {
+		return len(s.word1) - i
+	}
+
+	if s.dp[i][j] != UNSET {
+		return s.dp[i][j]
+	}
+
+	if s.word1[i] == s.word2[j] {
+		s.dp[i][j] = s.solve(i+1, j+1)
+	} else {
+		inserting := 1 + s.solve(i, j+1)
+		deleting := 1 + s.solve(i+1, j)
+		replacing := 1 + s.solve(i+1, j+1)
+
+		s.dp[i][j] = min(inserting, min(deleting, replacing))
+	}
+
+	return s.dp[i][j]
+}
+
+func (s *Solver) Solve() int {
+	return s.solve(0, 0)
+}
+
+func minDistance(word1 string, word2 string) int {
+	solver := makeSolver(word1, word2)
+	return solver.Solve()
+}