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@@ -0,0 +1,39 @@
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+func findRotateSteps(ring string, key string) int {
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+ // dp[i][j] means the min steps required to get the key[j] from ring[i],
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+ // then dp[0][0] is the answer.
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+ m, n := len(ring), len(key)
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+ if n == 0 {
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+ return 0
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+ }
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+ const INF int = 1e9
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+ dp := make([][]int, m)
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+ for i := range dp {
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+ dp[i] = make([]int, n+1)
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+ } // dp[i][j] = min(dp[i][j], dist(i, k) + dp[k][j+1])
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+ for j := n - 1; 0 <= j; j-- {
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+ for i := 0; i < m; i++ {
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+ dp[i][j] = INF
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+ for k := 0; k < m; k++ {
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+ if ring[k] == key[j] {
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+ step := minInt(abs(k-i), m-abs(k-i))
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+ dp[i][j] = minInt(dp[i][j], step+dp[k][j+1])
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+ }
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+ }
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+ }
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+ }
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+ return dp[0][0] + n
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+}
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+
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+func abs(x int) int {
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+ if x < 0 {
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+ return -x
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+ }
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+ return x
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+}
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+
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+func minInt(x, y int) int {
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+ if x < y {
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+ return x
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+ }
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+ return y
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+}
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