Problem:
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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: Accepted)

#include <stdio.h>
#include <string.h>
 
#define MAX 2000
 
void longest_common_subsequence(char x[], char y[]){
    int i,j,m,n;
    
    m = strlen(x);
    n = strlen(y);
    int a[m+1][n+1];
    
    for(i=0; i<=m; i++){
    for(j=0; j<=n; j++){
        a[i][j] = 0;
    }
    }
    
    for(i=1; i <= m; i++){
        for(j=1; j<=n; j++){
            if(x[i-1] == y[j-1])
            a[i][j] = a[i-1][j-1] + 1;
            else if(a[i-1][j] >= a[i][j-1])
            a[i][j] = a[i-1][j];
            else a[i][j] = a[i][j-1];
        }
    }
printf("%d\n",a[m][n]);    
    
}
 
int main(){
    int i,n;
    char x[MAX],y[MAX];
    
    scanf("%d",&n);
    for(i=0; i<n; i++){
        scanf("%s",x);
        scanf("%s",y);
        
        longest_common_subsequence(x,y);
    }
return 0;    
}