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@@ -0,0 +1,34 @@
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+func canCross(stones []int) bool {
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+ n := len(stones)
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+ m := make(map[int]int)
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+ for i := 1; i < n; i++ {
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+ m[stones[i]] = i
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+ }
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+ steps := make([][]int, n)
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+ steps[0] = []int{0}
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+ return dfs(stones, m, n, 0, &steps)
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+}
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+
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+func dfs(stones []int, m map[int]int, n, i int, steps *[][]int) bool {
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+ if i == n-1 {
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+ return true
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+ }
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+ for _, l := range (*steps)[i] {
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+ for j := maxInt(1, l-1); j <= l+1; j++ {
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+ if idx, ok := m[stones[i]+j]; ok {
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+ (*steps)[idx] = append((*steps)[idx], j)
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+ if dfs(stones, m, n, idx, steps) {
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+ return true
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+ }
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+ }
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+ }
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+ }
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+ return false
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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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