[LeetCode]Longest Common Subsequence@Golang

Longest Common Subsequence
Given two strings text1 and text2, return the length of their longest common subsequence.

A subsequence of a string is a new string generated from the original string with some characters(can be none) deleted without changing the relative order of the remaining characters. (eg, “ace” is a subsequence of “abcde” while “aec” is not). A common subsequence of two strings is a subsequence that is common to both strings.

If there is no common subsequence, return 0.

Example

Input: text1 = “abcde”, text2 = “ace”
Output: 3
Explanation: The longest common subsequence is “ace” and its length is 3.

Solution

func longestCommonSubsequence(text1 string, text2 string) int {
    m, n := len(text1), len(text2)
    A, B := []byte(text1), []byte(text2)
    
    pre := make([]int, m+1)
    cur := make([]int, m+1)
    
    for j:=0;j<n;j++{
        for i:=0;i<m;i++{
            temp := max(pre[i+1], cur[i])
            if B[j]==A[i]{
                cur[i+1] = max(temp, pre[i]+1)
            } else{
                cur[i+1] = temp
            }
        }
        cur, pre = pre, cur
    }
    return pre[m]
}

func max(a,b int)int {
    if a>b{
        return a
    }
    return b
}