Go: package main

import (
	"bufio"
	"os"
	"io"
	"strconv"
	"math"
	"fmt"
)

var (
	nstr   func() string
	stdout *bufio.Writer
)

func init() {
	nstr = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func main() {
	defer stdout.Flush()

	n := nint()
	xList := make([]string, n)
	yList := make([]string, n)

	for i:=0;i<n ;i++  {
		xList[i] = nstr()
		yList[i] = nstr()
	}

	for i := 0; i<n	; i++  {
		fmt.Println(lcs(xList[i], yList[i]))
	}

}

func lcs(x string, y string) int{
	var m = len(x)
	var n = len(y)

	c := make([][]int, m+1)
	for i:= range c{
		c[i] = make([]int, n+1)
	}
	for i:=	1;i<=m ;i++  {
		for j:=1;j<=n ;j++  {
			if x[i-1] == y[j-1]{
				c[i][j] = c[i-1][j-1] + 1
			}else{
				c[i][j] = int(math.Max(float64(c[i-1][j]), float64(c[i][j-1])))
			}


		}
	}
	return c[m][n]

}


func newReadString(ior io.Reader) func() string {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), int(1e+11))
	r.Split(bufio.ScanWords)

	return func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
}

func nint64() int64 {
	i, err := strconv.ParseInt(nstr(), 0, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func nint() int {
	return int(nint64())
}

func getIntSlice(n int) []int {
	b := make([]int, n)
	for i := 0; i < n; i++ {
		b[i] = nint()
	}
	return b
}

func getStringSlice(n int) []string {
	b := make([]string, n)
	for i := 0; i < n; i++ {
		b[i] = nstr()
	}
	return b
}

func gcd(x, y int) int {
	if y == 0 {
		return x
	}
	return gcd(y, x%y)
}

func lcm(x, y int) int {
	return x * y / gcd(x, y)
}

func contains(s []int, e int) bool {
	for _, a := range s {
		if a == e {
			return true
		}
	}
	return false
}

func bin(i int, prefix bool) string {
	i64 := int64(i)

	if prefix {
		return "0b" + strconv.FormatInt(i64, 2)
	} else {
		return strconv.FormatInt(i64, 2)
	}
}

func strReverse(s string) string {
	runes := []rune(s)
	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
		runes[i], runes[j] = runes[j], runes[i]
	}

	return string(runes)
}

C++: #include<iostream>
#include<string>
#include<algorithm>
using namespace std;

static const int N = 1000;

int lcs(string X, string Y) {
    int c[N+1][N+1];
    int m = X.size();
    int n = Y.size();
    int maxl = 0;
    X = ' ' + X;
    Y = ' ' + Y;
    for (int i = 1; i <= m; i++) {
        c[i][0] = 0;
    }
    for (int j = 1; j <= n; j++) {
        c[0][j] = 0;
    }

    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            if (X[i] == Y[j]) {
                c[i][j] = c[i - 1][j - 1] + 1;
            }else {
                c[i][j] = max(c[i - 1][j], c[i][j - 1]);
            }
            maxl = max(maxl, c[i][j]);
        }
    }

    return maxl;
}

int main()
{
    string s1, s2;
    int n; cin >> n;
    for (int i = 0; i < n; i++) {
        cin >> s1 >> s2;
        cout << lcs(s1, s2) << endl;
    }
    return 0;
}

C++: #include <cstdio>
#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

int lcs(string X, string Y) {
    int m = X.size();
    int n = Y.size();
    int c[m+1][n+1];
    int maxl = 0;
    X = ' ' + X;    // insert empty to X[0]
    Y = ' ' + Y;    // insert empty to Y[0]
    for (int i = 0; i <= m; i++) { c[i][0] = 0; }
    for (int j = 1; j <= n; j++) { c[0][j] = 0; }

    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            if (X[i] == Y[j]) {
                c[i][j] = c[i-1][j-1] + 1;
            } else {
                c[i][j] = max(c[i-1][j], c[i][j-1]);
            }
        }
    }

    return c[m][n];
}

int main() {
    int n;
    scanf("%d", &n);

    for (int i = 0; i < n; i++) {
        string s1, s2;
        cin >> s1 >> s2;
        printf("%d\n", lcs(s1, s2));
    }
    return 0;
}

C++: #include <iostream>
#include <algorithm>
#include<string.h>
using namespace std;
int LCS(char *x,char *y);
char x[1001], y[1001];
int lcs[1001][1001];
int main()
{
	int q,i,j;

	cin >> q;
	for (i = 0; i < q; i++) {
		cin >> x;
		cin >> y;
		cout << LCS(x, y) << endl;
	}
}

int LCS(char *x, char *y)
{
	int i, j;
	int len_x, len_y;
	len_x = strlen(x);
	len_y = strlen(y);
	
	for (i = 0; i < len_x; i++) {
		if (x[i] == y[0]) {
			lcs[i][0] = 1;
		}
		else {
			lcs[i][0] = 0;
		}
	}
	for (i = 0; i < len_y; i++) {
		if (x[0] == y[i]) {
			lcs[0][i] = 1;
		}
		else {
			lcs[0][i] = 0;
		}
	}

	for (i = 0; i < len_x; i++) {
		for (j = 0; j < len_y; j++) {
			if (x[i] == y[j]) {
				lcs[i][j] = lcs[i - 1][j - 1] + 1;
				//printf("lcs[%d][%d]=%d\n", i, j, lcs[i - 1][j - 1] + 1);
			}
			if (x[i] != y[j]) {
				lcs[i][j] = max(lcs[i - 1][j], lcs[i][j - 1]);
				//printf("lcs[%d][%d]=%d\n", i, j, max(lcs[i - 1][j], lcs[i][j - 1]));
			}
		}
	//cout << endl;

	}
	for (i = 0; i < len_x; i++) {
		for (j = 0; j < len_y; j++) {
			//printf("%d ", lcs[i][j]);
		}
		//cout << endl;
	}
	//cout << "len_x=" << len_x << endl << "len_y=" << len_y << endl;
			
	return lcs[i-1][j-1];
}

C++: #include <bits/stdc++.h>
using namespace std;

#define FOR( i, m, n )  for( int (i) = (m); (i) < (n); (i)++ )
#define REP( i, n )     FOR( i, 0, n )
#define ALL( a )        (a).begin(), (a).end()             

int main() {
	int n; cin >> n;

	int maxl;
	int	dp[1001][1001] = {};
	string s1, s2;
	REP( i, n ) {
		cin >> s1 >> s2;
		maxl = 0;
		FOR( j, 1, s1.size() + 1 ) {
			FOR( k, 1, s2.size() + 1 ) {
				if( s1[j] == s2[k] ) {
					dp[j][k] = dp[j - 1][k - 1] + 1;
				} else {
					dp[j][k] = max( dp[j - 1][k], dp[j][k - 1] );
				}
				maxl = max( dp[j][k], maxl );
			}
		}

		cout << maxl << endl;
	}
}

C++: #include<iostream>
#include<string>
#include<cstdio>
using namespace std;



int lcs(string x, string y){

  int m = x.length();
  int n = y.length();

  int c[m + 1][n + 1];

  for(int i = 0; i <= m; i++){
    c[i][0] = 0;
  }
  for(int i = 1; i <= n; i++){
    c[0][i] = 0;
  }

  for(int i = 1; i <= m; i++){
    for(int j = 1; j <= n; j++){
      if(x[i - 1] == y[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];
      }
  //    cout << "c" << i << j << c[i][j] << endl;
    }

  }

  return c[m][n];
}

int main(){

  int q;

  string x, y;

  cin >> q;

  for(int i = 0; i < q; i++){
    cin >> x;
    cin >> y;
    cout << lcs(x, y) << endl;
  }



  return 0;
}

C++: #include<iostream>
#include<algorithm>
#include<string>
using namespace std;
static const int N = 1000;
int lcs(string X, string Y) {
	int c[N+1][N+1];
	int m = X.size();
	int n = Y.size();
	int maxl = 0;

	X = ' ' + X;
	Y = ' ' + Y;
	for (int i = 1; i <= m; i++) c[i][0] = 0;
	for (int j = 1; j <= n; j++) c[0][j] = 0;

	for (int i = 1; i <= m; i++) {
		for (int j = 1; j <= n; j++) {
	
			if (X[i] == Y[j]) {
				c[i][j] = c[i - 1][j - 1] + 1;
			}
			else {
				c[i][j] = max(c[i - 1][j], c[i][j - 1]);
			}

			maxl = max(maxl,c[i][j]);
		}
		
	}
	return maxl;
}

int main() {
	string x, y;
	int n;
	cin >> n;
	for (int i = 0; i < n; i++) {
		cin >> x >> y;

		cout << lcs(x, y) << endl;
	}
	return 0;
	
}

C++: #include<iostream>
#include<string>
#include<cmath>
using namespace std;

int main(void){
  string st1, st2;
  int q, val[151][151];

  cin >> q;

  for(int i=0; i<q; i++){
    cin>>st1;
    cin>>st2;

    for(int j=0; j<=st1.length(); j++){
      for(int k=0; k<=st2.length(); k++){

	if(j==0 || k==0) val[j][k] = 0;
	else{

	  if(st1[j-1] == st2[k-1]){
	    val[j][k] = max(val[j-1][k], val[j][k-1]+1);
	  }else{
	    val[j][k] = max(val[j-1][k], val[j][k-1]);
	  }
	}

	if(val[j][k] >= st1.length() || val[j][k] >= st1.length()){
	  val[j][k] = min(st1.length(), st2.length());
	}
      }
    }

    for(int j=0; j<=st1.length(); j++){
      for(int k=0; k<=st2.length(); k++){
	cout << val[j][k] << " ";
      }
      cout << "\n";
    }

    cout << val[st1.length()][st2.length()] << "\n";
  }

  return 0;
}