Merge pull request #1 from TheAlgorithms/master

Update

Author: 0xbrayo

DIRECTORY.md

@@ -23,6 +23,7 @@
 
 ## Dynamic-Programming
   * [Longest-Palindromic-Subsequence](https://github.com/TheAlgorithms/Go/blob/master/dynamic-programming/longest-palindromic-subsequence.go)
+  * [Longestcommonsubsequence](https://github.com/TheAlgorithms/Go/blob/master/dynamic-programming/longestCommonSubsequence.go)
   * [Matrix-Multiplication](https://github.com/TheAlgorithms/Go/blob/master/dynamic-programming/matrix-multiplication.go)
   * [Rod-Cutting](https://github.com/TheAlgorithms/Go/blob/master/dynamic-programming/rod-cutting.go)
 

dynamic-programming/longestCommonSubsequence.go

@@ -0,0 +1,49 @@
+// LONGEST COMMON SUBSEQUENCE 
+// DP - 4
+// https://www.geeksforgeeks.org/longest-common-subsequence-dp-4/
+
+package longestcommonsubsequence
+// package main 
+
+// import "fmt"
+
+func max(a,b int) int{
+	if a>b{
+		return a
+	}
+	return b
+}
+
+func longestCommonSubsequence(a string, b string, m int, n int) int{
+	// m is the length of string a and n is the length of string b 
+	
+	// here we are making a 2d slice of size (m+1)*(n+1)
+	lcs:= make([][] int, m+1)
+	for i:=0;i<=m;i++{
+		lcs[i] = make([]int, n+1)
+	}
+
+	// block that implements LCS
+	for i:=0;i<=m;i++{
+		for j:=0;j<=n;j++{
+			if i==0 || j==0{
+				lcs[i][j] = 0;
+			}else if a[i-1] == b[j-1]{
+				lcs[i][j] = lcs[i-1][j-1]+1
+			}else{
+				lcs[i][j] = max(lcs[i-1][j], lcs[i][j-1])
+			}
+		}
+	}
+	// returning the length of longest common subsequence
+	return lcs[m][n]
+}
+
+// func main(){
+// 	// declaring two strings and asking for input 
+	
+// 	var a,b string 
+// 	fmt.Scan(&a, &b)
+// 	// calling the LCS function 
+// 	fmt.Println("The length of longest common subsequence is:", longestCommonSubsequence(a,b, len(a), len(b)))
+// }