61 lines
998 B
Go
61 lines
998 B
Go
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package main
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const UNSET int = -1
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type Solver struct {
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word1 string
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word2 string
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dp [][]int
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}
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func makeSolver(word1, word2 string) Solver {
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dp := make([][]int, len(word1))
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for i := range len(word1) {
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dp[i] = make([]int, len(word2))
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for j := range len(word2) {
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dp[i][j] = UNSET
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}
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}
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return Solver{
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word1: word1,
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word2: word2,
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dp: dp,
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}
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}
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func (s *Solver) solve(i, j int) int {
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if i >= len(s.word1) {
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return len(s.word2) - j
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}
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if j >= len(s.word2) {
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return len(s.word1) - i
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}
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if s.dp[i][j] != UNSET {
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return s.dp[i][j]
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}
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if s.word1[i] == s.word2[j] {
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s.dp[i][j] = s.solve(i+1, j+1)
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} else {
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inserting := 1 + s.solve(i, j+1)
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deleting := 1 + s.solve(i+1, j)
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replacing := 1 + s.solve(i+1, j+1)
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s.dp[i][j] = min(inserting, min(deleting, replacing))
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}
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return s.dp[i][j]
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}
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func (s *Solver) Solve() int {
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return s.solve(0, 0)
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}
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func minDistance(word1 string, word2 string) int {
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solver := makeSolver(word1, word2)
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return solver.Solve()
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}
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