LeetCode: Longest Increasing Subsequence

// https://code.dennyzhang.com/longest-increasing-subsequence
// Basic Ideas: dynamic programming
//    dp(i): ends with nums[i]
// Complexity: Time O(n^2), Space O(n)
func lengthOfLIS(nums []int) int {
    res := 0
    l := make([]int, len(nums))
    for i, num := range nums {
        l[i] = 1
        if i != 0 {
            for j:=i-1; j>=0; j-- {
                if nums[j] < num {
                    if l[j] + 1 > l[i] {
                        l[i] = l[j]+1
                    }
                }
            }
        }
        if l[i] > res { res = l[i] }
    }
    return res
}