Problem:
MathJax.Hub.Config({ tex2jax: { inlineMath: [["$","$"], ["\\(","\\)"]], processEscapes: true }});

Longest Common Subsequence

For given two sequences $X$ and $Y$, a sequence $Z$ is a common subsequence of $X$ and $Y$ if $Z$ is a subsequence of both $X$ and $Y$. For example, if $X = \{a,b,c,b,d,a,b\}$ and $Y = \{b,d,c,a,b,a\}$, the sequence $\{b,c,a\}$ is a common subsequence of both $X$ and $Y$. On the other hand, the sequence $\{b,c,a\}$ is not a longest common subsequence (LCS) of $X$ and $Y$, since it has length 3 and the sequence $\{b,c,b,a\}$, which is also common to both $X$ and $Y$, has length 4. The sequence $\{b,c,b,a\}$ is an LCS of $X$ and $Y$, since there is no common subsequence of length 5 or greater.

Write a program which finds the length of LCS of given two sequences $X$ and $Y$. The sequence consists of alphabetical characters.

Input

The input consists of multiple datasets. In the first line, an integer $q$ which is the number of datasets is given. In the following $2 \times q$ lines, each dataset which consists of the two sequences $X$ and $Y$ are given.

Output

For each dataset, print the length of LCS of $X$ and $Y$ in a line.

Constraints

$1 \leq q \leq 150$

$1 \leq$ length of $X$ and $Y$ $\leq 1,000$

$q \leq 20$ if the dataset includes a sequence whose length is more than 100

Sample Input 1

3
abcbdab
bdcaba
abc
abc
abc
bc

Sample Output 1

4
3
2

Reference

Introduction to Algorithms, Thomas H. Cormen, Charles E. Leiserson, Ronald L. Rivest, and Clifford Stein. The MIT Press.

Solution in C# (judge verdict: Time Limit Exceeded)

using System;

public class hello
{
    public static void Main()
    {
        var n = int.Parse(Console.ReadLine().Trim());
        for (int i = 0; i < n; i++)
        {
            var x = Console.ReadLine().Trim();
            var y = Console.ReadLine().Trim();
            var ans = Getls(x.Length-1, y.Length-1, x, y);
            Console.WriteLine(ans);

        }
    }
    public static int Getls(int i, int j, string x, string y)
    {

        if (i == -1 | j == -1) return 0;
        if (i > -1 && j > -1)
        {
            var x1 = x.Substring(i, 1);
            var y1 = y.Substring(j, 1);
            if (x1 == y1) return Getls(i - 1, j - 1, x, y) + 1;
            else return Math.Max(Getls(i - 1, j, x, y), Getls(i, j - 1, x, y));
        }
        else return 0;
    }
}