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@@ -0,0 +1,47 @@
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+const MAX_N int = 100
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+
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+var dp map[int]int
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+var length []int
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+
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+func removeBoxes(boxes []int) int {
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+ n := len(boxes)
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+ dp = make(map[int]int)
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+ length = make([]int, n)
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+ for i := 1; i < n; i++ {
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+ if boxes[i] == boxes[i-1] {
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+ length[i] = length[i-1] + 1
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+ }
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+ }
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+ return dfs(boxes, 0, len(boxes)-1, 0)
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+}
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+
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+func dfs(boxes []int, l, r, k int) int {
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+ // dp[l][r][k] = dp[l][r-1][0] + (k+1)^2, drop box[r]
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+ // = dp[l][p][k+1] + dp[p+1][r-1][0],
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+ // box[p] == box[j], remove boxes at [p+1, r-1] and attach
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+ // box[j] to box[p]
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+ if r < l {
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+ return 0
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+ }
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+ k += length[r]
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+ r -= length[r]
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+ key := ((l*MAX_N)+r)*MAX_N + k
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+ if val, ok := dp[key]; ok {
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+ return val
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+ }
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+ res := dfs(boxes, l, r-1, 0) + (k+1)*(k+1)
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+ for i := l; i < r; i++ {
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+ if boxes[i] == boxes[r] {
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+ res = maxInt(res, dfs(boxes, l, i, k+1)+dfs(boxes, i+1, r-1, 0))
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+ }
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+ }
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+ dp[key] = res
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+ return res
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+}
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+
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+func maxInt(x, y int) int {
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+ if x < y {
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+ return y
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+ }
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+ return x
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+}
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