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;


int lcs(string a, string b) {
	int dp[1009][1009];

	for (int i = 0; i <= a.size(); i++) {
		for (int j = 0; j <= b.size(); j++) {
			if (i == 0 || j == 0) dp[i][j] = 0;
			else if (a[i - 1] == b[j - 1])
				dp[i][j] = max(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[a.size()][b.size()];
}

int main() {
	int q;
	cin >> q;
	getchar();
	while (q--) {
		string a, b;
		getline(cin, a);
		getline(cin, b);
		/*cout << "=======" << a << "=======" << endl;
		cout << "=======" << b << "=======" << endl;*/
		cout << lcs(a, b) << endl;
	}
	return 0;
}

C++: #include "bits/stdc++.h"
// Custom Header {{{
#define ALL(x) x.begin(), x.end()
#define rep(i, s, n)      for(int i(s); i < int(n); ++i)
#define endl '\n'
#ifndef YDK
#define eprintf(...)
#endif
using namespace std;
using i64 = long long;
using pii = pair<i64, i64>;
template<class A, class B>inline bool chmax(A &a, const B &b){return b>a ? a=b,1 : 0;}
template<class A, class B>inline bool chmin(A &a, const B &b){return b<a ? a=b,1 : 0;}
constexpr const int INF  = 0x3f3f3f3f;
constexpr const i64 LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr const int MOD  = int(1e9) + 7;
// }}}

// Library {{{

// }}}

struct FastIO {
    FastIO() { cin.tie(nullptr); ios::sync_with_stdio(false); }
} fastIO_ydk ;

void slv()
{
    static int dp[1005][1005];

    string a, b;
    cin >> a >> b;

    dp[0][0] = 0;
    for (int i = 0; i < a.length(); ++i) {
        for (int j = 0; j < b.length(); ++j) {
            if (a[i] == b[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[a.length()][b.length()] << endl;

    return;
}

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

    for (int i = 0; i < n; ++i) slv();
    return 0;
}

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

#define MAX 1000

int c[MAX][MAX];

int lcs(string A, string B)  {
    int a = A.length();
    int b = B.length();
    int maxl = 0;

    A = ' ' + A;
    B = ' ' + B;
    //配列を作る
    for(int i=0; i<a; i++) {
        c[i][0] = 0;
    }
    for(int j=0; j<b; j++) {
        c[0][j] = 0;
    }
    for(int i=1; i<=a; i++) {
        for(int j=1; j<=b; j++) {
            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]);
            }
            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<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 <iostream>
#include <fstream>
#include <sstream>
#include <vector>
#include <string>
#include <algorithm>
#include <queue>
#include <stack>
#include <map>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <limits>
#include <random>
#include <complex>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <string.h>
#include <iomanip>
using namespace std;

#define REP(i,n) for(int (i)=0;(i)<(int)(n);(i)++)
#define RREP(i,n) for(int (i)=(int)(n)-1;i>=0;i--)
#define REMOVE(Itr,n) (Itr).erase(remove((Itr).begin(),(Itr).end(),n),(Itr).end())
typedef long long ll;

string LongestCommonSubsequence(string s1, string s2) {
    int N = (int) s1.size();
    int M = (int) s2.size();
    vector < vector < int > > dp(N + 1, vector < int > (M + 1, 0));
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < M; j++) {
            if (s1[i] == s2[j]) {
                dp[i + 1][j + 1] = dp[i][j] + 1;
            } else {
                dp[i + 1][j + 1] = max(dp[i][j + 1], dp[i + 1][j]);
            }
        }
    }
    string ret;
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < M; j++) {
            if(dp[i + 1][j + 1] == ret.size() + 1){
                ret = ret + s2[j];
            }
        }
    }
    return ret;
}

int main() {

    int N; cin >> N;

    REP(i,N) {
        string a,b; cin >> a >> b;
        cout << LongestCommonSubsequence(a,b).size() << endl;
    }

    return 0;
}

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

using namespace std;

int maxa[1000];
int main(){
  int n;
  int k;
  int count;
  cin>>n;
  char X[1001];
  char Y[1001];
  for(int i=0;i<n;i++){
    cin>>X;
    cin>>Y;
    k=0;
    for(int a=0;X[a]!='\0';a++){
    count=0;
      for(int s=a;X[s]!='\0';s++){
	for(int j=k;Y[j]!='\0';j++){
	  if(X[s]==Y[j]){
	    count++;
	    k=j;
	    break;
	  }
	}
      }
      if(maxa[i]<count)maxa[i]=count;
    }
  }
  for(int i=0;i<n;i++){
    cout<<maxa[i]<<endl;
  }
  
  return 0;
}