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 <array>
#include <vector>
#include <deque>
#include <set>
#include <unordered_set>
#include <map>
#include <unordered_map>
#include <string>
#include <algorithm>
#include <numeric>
#include <functional>
#include <iterator>
#include <tuple>
#include <utility>
#include <limits>
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <cstdint>
#include <cassert>

using namespace std;

#define FOR(i, start, end) for(int i = (start); i < (end); ++i)
#define REP(i, n) FOR(i, 0, n)

constexpr int N = 1000;

int dp[N+1][N+1];

int solve(const string& x, const string& y)
{
    int m = x.size();
    int n = y.size();

    FOR(i, 0, m+1)
        dp[i][0] = 0;
    FOR(j, 0, n+1)
        dp[0][j] = 0;

    FOR(i, 1, m+1) {
        FOR(j, 1, n+1) {
            if(x[i-1] == y[j-1])
                dp[i][j] = dp[i-1][j-1] + 1;
            else
                dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
        }
    }

    return dp[m][n];
}

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

    REP(_, n) {
        string x, y;
        cin >> x;
        cin >> y;

        int lcs_len = solve(x, y);
        cout << lcs_len << "\n";
    }

    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define REP(i,n) for (int i = 0; i < n; i++)
typedef long long ll;
// Welcome to my source code!

int lcs(string x, string y) {
    int m = x.size();
    int n = y.size();
    int c[m+1][n+1] = {};
    int maxv = 0;
    x = ' ' + x;
    y = ' ' + y;
    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]);
            }
            maxv = max(maxv, c[i][j]);
        }
    }
    return maxv;
}

int main() {
    int q;
    string x, y;
    cin >> q;
    REP(i,q) {
        cin >> x >> y;
        cout << lcs(x,y) << endl;
    }
}

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

static const int N = 1000;

int lcs(string X, string Y) {
    //DP memotable: c
    int c[N+1][N+1];
    int xSize = X.size();
    int ySize = Y.size();
    int maxl = 0;
    //first char will be empty because of dp table
    X = ' ' + X;
    Y = ' ' + Y;
    for (int i = 0; i <= xSize; i++) c[i][0] = 0;
    for (int j = 0; j <= ySize; j++) c[0][j] = 0;

    for (int i = 1; i <= xSize; i++) {
        for (int j = 1; j <= ySize; 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]);
        }
    }
    /*
    for (int i = 1; i <= xSize; i++) {
        for (int j = 1; j <= ySize; j++) {
            cout << c[i][j] << " ";
        }
        cout << endl;
    }
    */
    return maxl;
}

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

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

using namespace std;

string a,b;

int lcs(int i,int j){
  if(i==0 || j==0) return 0;
  if(a[i]==b[j]){
    return lcs(i-1,j-1)+1;
  }else{
    return max(lcs(i,j-1),lcs(i-1,j));
  }
}

int main(){
  int n; cin>>n;
  for(int i=0;i<n;i++){
    cin>>a>>b;
    a = ' ' + a;
    b = ' ' + b;
    cout<<lcs(a.size()-1,b.size()-1)<<endl;
  }
}

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 = 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]);
    }
    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 <bits/stdc++.h>

#define int             long long
#define FOR( i, m, n )  for( int (i) = (m); (i) < (n); (i)++ )
#define REP( i, n )     FOR( i, 0, n )
#define REPR( i, m )    for( int (i) = (m); (i) >= 0; (i)-- )
#define REPONE( i, n )  FOR( i, 1, n + 1 )
#define ALL( a )        (a).begin(), (a).end()
#define MP              make_pair

using namespace std;
using P = pair<int, int>;

template<class T>bool chmax( T& a, const T& b ) { if( a < b ) { a = b; return 1; } return 0; }
template<class T>bool chmin( T& a, const T& b ) { if( a > b ) { a = b; return 1; } return 0; }

const int INF = 1e9;
const int MOD = 1e9 + 7;

int dp[1001][1001];

signed main(){
    int N; cin >> N;
    REP( i, N ){
        string s, t; cin >> s >> t;
        REP( i, s.size() ){
            REP( j, t.size() ){
                if( s[i] == t[j] ){
                    dp[i + 1][j + 1] = dp[i][j] + 1;
                }else{
                    dp[i + 1][j + 1] = max( dp[i + 1][j], dp[i][j + 1] );
                }
            }
        }

        cout << dp[s.size()][t.size()] << endl;
    }
}