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<stdlib.h>
#include<string.h>
#include<math.h>
#define N 1000
char s1[N],s2[N];
int lcs(){
  int i,j,maxl=0;
  int c[N+1][N+1];
  int m=strlen(s1);
  int n=strlen(s2);
  for(i=1;i<=m;i++){
    for(j=1;j<=n;j++){
      c[i][j]=0;
    }
  }
  for(i=1;i<=m;i++){
    for(j=1;j<=n;j++){
      if(s1[i-1]==s2[j-1]){
	c[i][j]=c[i-1][j-1]+1;
      }
      else{
	if(c[i-1][j]>c[i][j-1]){
	  c[i][j]=c[i-1][j];
	}
	else{
	  c[i][j]=c[i][j-1];
	}
      }
      if(maxl>c[i][j]){
	maxl=maxl;
      }
      else{
	maxl=c[i][j];
      }
    }
  }
  return maxl; 
}
int main(){
  int i,j,n,b;
  scanf("%d",&n);
  for(i =0;i < n;i++){
    scanf("%s",s1);
    scanf("%s",s2);
    b=lcs();
    printf("%d\n",b);
  }
  return 0;
}