30 lines
692 B
Go
30 lines
692 B
Go
// Package q84 implements a solution for https://leetcode.com/problems/largest-rectangle-in-histogram/
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package q84
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func largestRectangleArea(heights []int) int {
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var largest int
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st := make([][2]int, 0, 256) // x index, height
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for x, h := range heights {
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minX := x
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for len(st) > 0 && st[len(st)-1][1] > h {
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largest = max(largest, st[len(st)-1][1]*(x-st[len(st)-1][0]))
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minX = min(minX, st[len(st)-1][0])
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st = st[:len(st)-1]
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}
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if len(st) > 0 && st[len(st)-1][1] == h {
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continue
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}
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st = append(st, [2]int{minX, h})
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}
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for i := range st {
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x, h := st[i][0], st[i][1]
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largest = max(largest, h*(len(heights)-x))
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}
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return largest
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}
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var _ = largestRectangleArea
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