https://leetcode.com/problems/next-greater-element-i

next-greater-element-i.go

func nextGreaterElement(nums1 []int, nums2 []int) []int {
    stack := []int{}
    table := make(map[int]int)
    
    for _, num := range nums2 {
        for len(stack) > 0 && stack[len(stack) - 1] < num {
            item := stack[len(stack) - 1]
            stack = stack[:len(stack) - 1]
            table[item] = num
        }
        
        stack = append(stack, num)
    }
    
    for len(stack) > 0 {
        item := stack[len(stack) - 1]
        stack = stack[:len(stack) - 1]
        table[item] = -1
    }
    
    result := []int{}
    
    for _, num := range nums1 {
        result = append(result, table[num])
    }
    
    return result
}