golang力扣leetcode 84.柱状图中最大的矩形

package main
func largestRectangleArea(heights []int) int {
  if len(heights) == 0 {
    return 0
  }
  var stack []int
  max := 0
  for i := 0; i <= len(heights); i++ {
    var cur int
    if i == len(heights) {
      cur = 0
    } else {
      cur = heights[i]
    }
    for len(stack) != 0 && cur <= heights[stack[len(stack)-1]] {
      idx := stack[len(stack)-1]
      stack = stack[:len(stack)-1]
      h := heights[idx]
      peek := 0
      w := i
      if len(stack) != 0 {
        peek = stack[len(stack)-1]
        w = i - peek - 1
      }
      max = Max(max, w*h)
    }
    stack = append(stack, i)
  }
  return max
}
func Max(a, b int) int {
  if a > b {
    return a
  }
  return b
}
func main() {
}