Go: package main

import (
	. "fmt"
    "math"
)

// func init() { Println("----------------------------------------") }

func main() {
    const L_MAX = 1003

	var q int
	Scanf("%d", &q)
	X := make([]string, 0, 150)
	Y := make([]string, 0, 150)
	for i := 0; i < 2 * q; i++ {
	    var tmp string
	    Scanf("%s", &tmp)

	    if i % 2 == 0 {
	        X = append(X, tmp)
	    } else {
	        Y = append(Y, tmp)
	    }
	}

    for i := 0; i < q; i++ {
        dp := make([][]int, L_MAX)
        for k, _ := range dp {
            dp[k] = make([]int, L_MAX)
        }

        x, y := X[i], Y[i]

        // init
        isXFound := false
        for c := 0; c < len(x); c++ {
            if isXFound || y[0] == x[c] {
                dp[0][c] = 1
                isXFound = true
            }
        }
        isYFound := false
        for r := 0; r < len(y); r++ {
            if isYFound || x[0] == y[r] {
                dp[r][0] = 1
                isYFound = true
            }
        }

        for r := 1; r < len(y); r++ {
            for c := 1; c < len(x); c++ {
                // dp[r][c]
                if x[c] == y[r] {
                    dp[r][c] = int(math.Max(float64(dp[r - 1][c - 1] + 1), float64(dp[r][c])))
                }

                dp[r][c] = int(math.Max(float64(dp[r][c]), math.Max(float64(dp[r - 1][c]), float64(dp[r][c - 1]))))
            }
        }
        Println(dp[len(y) - 1][len(x) - 1])

        // LCSも求めておく
        // ans := ""
        // r, c := len(y) - 1, len(x) - 1
        // for r >= 0 && c >= 0 {
        //     if y[r] == x[c] {
        //         ans = string(x[c]) + ans
        //         r--
        //         c--
        //     } else {
        //         if dp[r - 1][c] > dp[r][c - 1] {
        //             r--
        //         } else {
        //             c--
        //         }
        //     }
        // }
        // Println(ans)
    }
}

C++: #include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define MM 1000000000
#define MOD MM+7
#define MAX 301000
#define MAP 110
#define initial_value -1
#define Pair pair<int,int>
#define chmax(a,b) (a<b ? a=b:0)
#define chmin(a,b) (a>b ? a=b:0)
ll INF = 1e18;
int dx[4] = {-1,0,1,0};
int dy[4] = {0,-1,0,1};
//union_find
int par[100];
int depth[100];
ll N;
ll x[20],c[20],v[20];
string s,t;

int lcs(string x, string y){
    int dp[1010][1010];
    int m = x.size();
    int n = y.size();
    int mx = 0;
    x = ' ' + x;
    y = ' ' + y;
    for(int i = 0; i <= m; i++) dp[i][0] = 0;
    for(int i = 1; i <= n; i++) dp[0][i] = 0;
    for(int i = 1; i <= m; i++){
        for(int j = 1; j <= n; j++){
            if(x[i] == y[i]){
                dp[i][j] = dp[i-1][j-1] + 1;
            } else {
                dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
            }
            mx = max(mx, dp[i][j]);
        }
    }
    return mx;
}
int main(){
    cin >> N;
    for(int i = 0; i < N; i++){
        cin >> s >> t;
        cout << lcs(s,t) << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

int main() {

    int n;
    string str1, str2;

    cin >> n;

    for(int cnt = 0; cnt < n; ++cnt) {

        cin >> str1 >> str2;

        int dp[str1.size() + 1][str2.size() + 1];

        for(int i = 0; i <= str1.size(); ++i) {
            dp[i][0] = 0;
        }

        for(int i = 0; i <= str2.size(); ++i) {
            dp[0][i] = 0;
        }

        for(int i = 1; i <= str1.size(); ++i) {
            for(int j = 1; j <= str2.size(); ++j) {
                if(str1[i - 1] == str2[j - 1]) {
                    dp[i][j] = dp[i - 1][j - 1] + 1;
                } else {
                    dp[i][j] = max(dp[i - 1][j], dp[i][j - 1]);
                }
            }
        }

        cout << dp[str1.size()][str2.size()] << endl;

    }

}

C++: 
//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=ALDS1_10_C&lang=jp




#include <iostream>
#include <vector>
#include <algorithm>
#include <string>

#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)

using namespace std;

const int MAX_q=160;
const int MAX_L=1010;
bool done[MAX_L][MAX_L];
int memo[MAX_L][MAX_L];
int q;
string x,y;

int LCS(int i,int j)
{
    int res;

    if(i<0) return 0;
    if(j<0) return 0;

    if (done[i][j]) return memo[i][j];

    else if(x[i]==y[j])
    {
        res=LCS(i-1,j-1)+1;
    }
    else{
        int res1=LCS(i-1,j);
        int res2=LCS(i,j-1);
        res=max(res1,res2);
    }
    done[i][j]=true;
    memo[i][j]=res;
    return res;
}

int main()
{
    int res;
    cin>>q;
    rep(i,q)
    {
        cin>>x>>y;
        res=LCS(x.length()-1,y.length()-1);
        cout<<res<<"\n";
        rep(j,MAX_L)
        {
            rep(k,MAX_L)
            {
                done[j][k]=false;
            }
        }
    }


    return 0;
}

C++: #include<iostream>
#include<cstring>
using namespace std;
int L[1001][1001];
int getc(int i,int j){
    if(i>=0&&j>=0)
        return L[i][j];
    else
        return 0;
}
int main(){
    int N;
    string X,Y;
    cin >> N;
    for(int k=0;k<N;++k){
        cin>>X>>Y;
        for(int i=0;i<X.length();++i){
            for(int j=0;j<Y.length();++j){
                if(X[i]==Y[j]){
                    L[i][j]=getc(i-1,j-1)+1;
                }
                else{
                    L[i][j]=max(getc(i-1,j),getc(i,j-1));
                }
            }
        }
        cout <<L[X.length()-1][Y.length()-1]<< endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
const int INF = 1e9;
const int MOD = 1e9+7;
const long long LINF = 1e18;
#define dump(x)  cout << 'x' << ' = ' << (x) << ` `;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define rep(i,n) for(int i=0;i<(n);++i)
#define REPR(i,n) for(int i=n;i>=0;i--)
#define FOREACH(x,a) for(auto& (x) : (a) )
typedef long long ll;
using namespace std;
typedef pair<ll, ll> P;

const int MAX_N = 1333;

int dp[MAX_N][MAX_N];

int LCS(string &s, string &t) {
    int n=s.length(); int m=t.length();
    if (!n||!m) return 0;
    memset(dp,-1,sizeof(dp));
    rep(i,n+1) dp[i][0]=0;
    rep(i,m+1) dp[0][i]=0;

    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= m; ++j) {
            if (s[i-1]==t[j-1]) dp[i][j]=max({dp[i-1][j-1]+1,dp[i-1][j],dp[i][j-1]});
            else dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
        }
    }

    return dp[n][m];
}

int main(int argc, char const *argv[]) {
    int q;cin>>q;
    rep(i,q) {
        string s,t;
        cin>>s>>t;
        cout << LCS(s,t) << endl;
    }
    return 0;
}

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

int main() {
  std::ios::sync_with_stdio(false);
  cout.tie(0);
  cin.tie(0);
  int N;
  cin>>N;
  string S1,S2;
  for (int k=0; k<N; k++) {
    cin>>S1>>S2;
    int m=S1.length();
    int n=S2.length();
    S1=' '+S1;
    S2=' '+S2;
    int lcs[m+1][n+1];
    for (int i=1; i<=m; i++) {
      lcs[i][0]=0;
    }
    for (int j=1; j<=n; j++) {
      lcs[0][j]=0;
    }
    int maxl=0;
    for (int i=1; i<=m; i++) {
      for (int j=1; j<=n; j++) {
        if (S1[i]==S2[j]) {
          lcs[i][j]=lcs[i-1][j-1]+1;
        }
        else {
          lcs[i][j]=max(lcs[i-1][j],lcs[i][j-1]);
        }
        maxl=max(maxl,lcs[i][j]);
      }
    }
    cout<<maxl<<endl;
  }
  return 0;
}