Go: package main

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

//Util
func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

func maxInt(a, b int) int {
	if a > b {
		return a
	} else {
		return b
	}
}

func minInt(a, b int) int {
	if a > b {
		return b
	} else {
		return a
	}
}

func absInt(a int) int {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func absFloat64(a float64) float64 {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func minFloat64(a, b float64) float64 {
	if a > b {
		return b
	} else {
		return a
	}
}

func str2Int(s string) int {
	n, _ := strconv.Atoi(s)
	return n
}

//Main
var sc = bufio.NewScanner(os.Stdin)
var q int
var X, Y string

func lcs(X, Y string) int {
	lenX := len(X)
	lenY := len(Y)
	dp := make([][]int, lenX+1)
	for i := 0; i < lenX+1; i++ {
		dp[i] = make([]int, lenY+1)
	}

	res := 0
	for i := 1; i < lenX+1; i++ {
		for j := 1; j < lenY+1; j++ {
			if X[i-1] == Y[j-1] {
				dp[i][j] = dp[i-1][j-1] + 1
			} else {
				dp[i][j] = maxInt(dp[i-1][j], dp[i][j-1])
			}
			//fmt.Println(dp)
			res = maxInt(res, dp[i][j])
		}

	}
	return res
}

func main() {
	sc.Split(bufio.ScanWords)
	q = nextInt()

	for i := 0; i < q; i++ {
		X = nextStr()
		Y = nextStr()

		fmt.Println(lcs(X, Y))
	}
}

C++: #include <iostream>
#define INF 1000000
using namespace std;

int q;
string x,y;
int _dp[1010][1010];
int result[150];

int dp(int posx,int posy){
	if(_dp[posx][posy]) return _dp[posx][posy];
	if(posx == 0 || posy == 0){
		_dp[posx][posy] == 0;
		return 0;
	}else{
		int max = dp(posx-1,posy);
		if(max < dp(posx,posy-1)) max = dp(posx, posy-1);
		if(x[posx-1] == y[posy-1] && max < dp(posx-1,posy-1)+1)
			max = dp(posx-1,posy-1)+1;
		_dp[posx][posy] = max;
		return max;
	}
}

int main(void){
	cin >> q;
	
	for(int i=0; i<q; i++){
		cin >> x >> y;
		result[i] = dp(x.size() ,y.size());
		std::fill((int*) _dp, (int*) (_dp + 1010), 0);
	}
	
	for(int i=0; i<q; i++) cout << result[i] << endl;
	
	return 0;
}

C++: #include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
using namespace std;
int main(){
  char str1[1000],str2[1000];
  int LCS[1000][1000]={0};
  int length1,length2;
  int n;
  scanf("%d",&n);
  for(int s=1;s<=n;s++){
   while(cin>>str1>>str2){
     length1=strlen(str1);
     length2=strlen(str2);
     for(int i=0;i<=length1-1;i++){
       LCS[i][0]=0;
     }
     for(int j=0;j<=length2-1;j++){
       LCS[0][j]=0;
     }
     for(int i=1;i<=length1;i++){
       for(int j=1;j<=length2;j++){
         if(str1[i-1]==str2[j-1]) {
           LCS[i][j]=LCS[i-1][j-1]+1;
         }
         else LCS[i][j]=max(LCS[i-1][j],LCS[i][j-1]);
       }
     }
     printf("%d\n",LCS[length1][length2]);
   }
 }
   return 0;
}

C++: #if 0
???????????????????????????Z???Z[1000][1000]??§???????????£??????????????????????????£??????
#endif


#include <iostream>
#include <algorithm>
#include <string>
using namespace std;

int N,len1,len2;
string X,Y;
int Z[1010][1010];

int main() {
  cin >> N;
  for (int i=0; i<N; i++){
    cin >> X >> Y;
    len1 = X.length();
    len2 = Y.length();
    for (int i=1; i<=len1; i++){
      for (int j=1; j<=len2; j++){
       if (X[i-1] == Y[j-1]){
         Z[i][j] = Z[i-1][j-1] + 1;
       }
       else if (Z[i][j-1] > Z[i-1][j]){
         Z[i][j] = Z[i][j-1];
       }
       else{
         Z[i][j] = Z[i-1][j];
       }
     }
   }
   cout << Z[len1][len2] << endl;
 }
}

C++: #include <bits/stdc++.h>
using namespace std;
#define For(I,A,B) for(int I=(A); I < (B); ++I)
int main()
{
int t;
cin>>t;
while(t--){
int a[1000]={0},b[1000]={0},c[200][200];
int x,y,z,k=0,l,i,j;

 For(i,0,200)
 For(j,0,200)
 c[i][j]=0;


 cin>>x>>y;
 For(i,0,x+1)
 For(j,0,y+1)
 c[i][j]=0;
 For(i,1,x+1) cin>>a[i];
 For(i,1,y+1) cin>>b[i];

 For(i,1,x+1)
 For(j,1,y+1)
 {
     if(a[i]==b[j]) c[i][j]=c[i-1][j-1]+1;
     else  c[i][j]=max(c[i-1][j],c[i][j-1]);
 }
    cout<<c[x][y]<<endl;

}
}
    return 0;
}

C++: #define _USE_MATH_DEFINES
#include<iostream>
#include<algorithm>
#include<string>
#include<iomanip>
#include<cmath>
#include<vector>
#include<deque>
#include<queue>
#include<map>
#include<set>
#define ll long long
#define vll vector<ll>
#define dou(s) atof(s.c_str())
#define lon(s) atoll(s.c_str())
#define str(n) to_string(n)
#define rep(i,a,b) for(ll i=a;i<b;i++)
#define rrep(i,b,a) for(ll i=b;i>=a;i--)
#define ALL(a) a.begin(),a.end()
#define rALL(a) a.rbegin(),a.rend()
#define line "\n"
#define mav(a) (*max_element(ALL(a)))
#define miv(a) (*min_element(ALL(a)))
#define vfind(a,n) (find(ALL(a),n)-a.begin())
#define prque priority_queue
#define MOD 1000000007ll
using namespace std;
void solve();
int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	solve();
}

//nCk(mod p)
/*ll fac[510000], finv[510000], inv[510000];
void cmodf(ll p = MOD) {
	fac[0] = fac[1] = 1;
	finv[0] = finv[1] = 1;
	inv[1] = 1;
	rep(i, 2, 510000) {
		fac[i] = fac[i - 1] * i%p;
		inv[i] = p - inv[p%i] * (p / i) % p;
		finv[i] = finv[i - 1] * inv[i] % p;
	}
}
ll cmod(ll n, ll k, ll p = MOD) {
	return fac[n] * (finv[k] * finv[n - k] % p) % p;
}*/

//最大公約数
ll gcd(ll n, ll m) {
	ll k = n % m;
	while (k != 0) { n = m; m = k; k = n % m; }
	return m;
}
ll gcd(vector<ll> a) {
	rep(i, 1, a.size()) {
		ll k = a[i - 1] % a[i];
		while (k != 0) {
			a[i - 1] = a[i];
			a[i] = k;
			k = a[i - 1] % a[i];
		}
	}
	return a.back();
}

//最小公倍数
ll lcm(ll n, ll m) {
	ll t = n * m, k = n % m;
	while (k != 0) { n = m; m = k; k = n % m; }
	return t / m;
}
ll lcm(vector<ll> a) {
	ll n;
	rep(i, 1, a.size()) {
		n = a[i - 1] * a[i];
		ll k = a[i - 1] % a[i];
		while (k != 0) {
			a[i - 1] = a[i];
			a[i] = k;
			k = a[i - 1] % a[i];
		}
		n /= a[i];
		a[i] = n;
	}
	return n;
}

//keyの小さい方から探していった時に初めてvalueがjoken以上になる時のkey（keyが増えたらvalueも増えるか同じになるとき）
ll value(ll key) {
	/*変更*/
	return 0;
}
ll mini(ll lkey, ll rkey/*ここも調べる*/, ll joken) {
	ll mkey;
	while (lkey != rkey) {
		mkey = (lkey + rkey) / 2;
		if (value(mkey) >= joken)rkey = mkey;
		else lkey = mkey + 1;
	}
	return rkey;
}

//ペア配列の整理
struct pea { ll n, m; };
void msort(vector<pea> &a, bool k = true) {
	struct hikakukansu {
		static bool unstable(const pea &x, const pea &y) { return x.m < y.m; }
		static bool stable(const pea &x, const pea &y) { return (x.m == y.m ? x.n < y.n : x.m < y.m); }
	};
	if (k)sort(ALL(a), hikakukansu::unstable);
	else sort(ALL(a), hikakukansu::stable);
}

//変数定義

//再帰関数

//アルゴリズム
void solve() {
	ll n; cin >> n;
	string s, t;
	rep(i, 0, n) {
		cin >> s >> t;
		s = ' ' + s;
		t = ' ' + t;
		vector<vll> dp(s.size(), vll(t.size()));
		rep(i, 0, t.size())dp[0][i] = 0;
		rep(i, 0, s.size())dp[i][0] = 0;
		ll ma = 0;
		rep(i, 1, s.size()) {
			rep(j, 1, t.size()) {
				if (s[i] == t[j]) {
					dp[i][j] = dp[i - 1][j - 1] + 1;
				}
				else {
					dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
				}
				ma = max(ma, dp[i][j]);
			}
		}
		cout << ma << line;
	}
}

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

int dp[1001][1001];
int main() {
	int b;
	scanf("%d", &b);
	char e[1001];
	char f[1001];
	for (int c = 0; c < b; c++) {
		scanf("%s%s", e, f);
		for (int g = 0; g <= strlen(e); g++) {
			for (int h = 0; h <= strlen(f); h++) {
				dp[g][h] = 0;
			}
		}
		for (int g = 0; g < strlen(e); g++) {
			for (int h = 0; h < strlen(f); h++) {
				if (e[g] == f[h]) {
					dp[g+1][h+1] = dp[g][h] + 1;
				}
				else {
					if (dp[g][h + 1] > dp[g + 1][h])dp[g + 1][h + 1] = dp[g][h + 1];
					else dp[g + 1][h + 1] = dp[g+1][h];
				}
			}
		}
		printf("%d\n", dp[strlen(e)][strlen(f)]);
	}
}