/**
Given two strings text1 and text2, return the length of their longest common subsequence. If there is no common subsequence, return 0.
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.
For example, "ace" is a subsequence of "abcde".
A common subsequence of two strings is a subsequence that is common to both strings.
Example 1:
Input: text1 = "abcde", text2 = "ace"
Output: 3
Explanation: The longest common subsequence is "ace" and its length is 3.
**/
class Solution {
public int longestCommonSubsequence(String text1, String text2) {
int m = text1.length(), n = text2.length();
int mat[][] = new int[m+1][n+1];
for(int i = 0 ; i<=m;i++)
mat[i][0] = 0;
for(int i = 0 ; i<=n;i++)
mat[0][i] = 0;
for(int i = 1 ; i<=m;i++) {
for(int j = 1 ; j<=n;j++) {
if(text1.charAt(i-1) == text2.charAt(j-1))
mat[i][j] = mat[i-1][j-1] + 1;
else {
mat[i][j] = Math.max(mat[i-1][j],mat[i][j-1]);
}
}
}
return mat[m][n];
}
}