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 <iostream>
#include <string>

using namespace std;

int main(){

  int q;

  cin >> q;


  for(int k = 0; k < q; k++){
    string a, b;
    cin >> a >> b;
    int dp[a.size()][b.size()] = {};
    //初期設定
    if(a[0] == b[0]){
      dp[0][0] = 1;
    }
    for(int i = 1; i < a.size(); i++){
      if(a[i] == b[0] || dp[i-1][0] == 1){
        dp[i][0] = 1;
      }
    }
    for(int j = 1; j < b.size(); j++){
      if(a[0] == b[j] || dp[0][j-1] == 1){
        dp[0][j] = 1;
      }
    }
    for(int i = 1; i < a.size(); i++){
      for(int j = 1; j < b.size(); j++){
        if(a[i] == b[j]){
          if(dp[i-1][j-1] >= dp[i-1][j] && dp[i-1][j-1] >= dp[i][j-1]){
            dp[i][j] = dp[i-1][j-1]+1;

          }
          else{
            dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
          }
        }
        else{
          dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
        }
      }
    }
    cout << dp[a.size()-1][b.size()-1] << "\n";
  }

  return 0;
}

C++: #include <iostream>

using namespace std;

int LCS[1001][1001];

int lcs(string X, string Y)
{
    int m = X.size();
    int n = Y.size();
    X = ' ' + X;
    Y = ' ' + Y;
    for(int i = 0; i <= m; i++)
        LCS[i][0] = 0;
    for(int j = 1; j <= n; j++)
        LCS[0][j] = 0;
    
    for(int i = 1; i <= m; i++)
    {
        for(int j = 1; j <= n; j++)
        {
            if(X[i] == Y[j])
                LCS[i][j] = LCS[i - 1][j - 1] + 1;
            else
                LCS[i][j] = max(LCS[i][j - 1], LCS[i - 1][j]);
        }
    }
    return LCS[m][n];
}

int main()
{
    int q;
    cin >> q;
    string X;
    string Y;
    for(int i = 0; i < q; i++)
    {
        cin >> X;
        cin >> 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) {
  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 q;
  cin >> q;

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

  return 0;
}

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

int main(){
	int q;
	scanf(" %d", &q);
	for(int i=0; i<q; ++i){
		string a, b;
		cin >> a >> b;
		
		int m=a.size(), n=b.size();
		
		string x=" "+a;
		string y=" "+b;
		
		int c[1001][1001]={0};
		for(int i=1; i<=m; ++i) c[i][0]=0;
		for(int i=1; i<=n; ++i) c[0][n]=0;
		
		int ans=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][j-1], c[i-1][j]);
				
				ans=max(ans,c[i][j]);		
			}
		}
		
		printf("%d\n", ans);
	}
}

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

#define MAX_N 1000
#define MAX_M 1000

int n, m;
std::string s, t;

int dp[MAX_N+1][MAX_M+1];

void solve() {
  for (int i = 0; i < n; ++i) {
    for (int j = 0; j < m; ++j) {
      if (s[i+1] == t[j+1]) {
        dp[i+1][j+1] = dp[i][j] + 1;
      }
      else {
        dp[i+1][j+1] = std::max(dp[i][j+1], dp[i+1][j]);
      }
    }
  }
}

int main() {
  int q;
  std::cin >> q;
  for (int i = 0; i < q; ++i) {
    std::cin >> s >> t;
    n = s.size();
    m = t.size();
    solve();
    std::cout << dp[n][m] << std::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>
using namespace std;
int a[1003][1003];
int main()
{
    int t;
    cin>>t;
    while(t--)
    {
        string x,y;
        cin>>x>>y;
        int len1=x.size();
        int len2=y.size();

        memset(a,0,sizeof(a));
        for(int i=0; i<len1; i++)
        {
            for(int j=0; j<len2; j++)
            {
                if(x[i]==y[j])
                {
                    a[i+1][j+1]=a[i][j]+1;
                }
                else a[i+1][j+1]=max(a[i][j+1],a[i+1][j]);
            }
        }
        cout<<a[len1][len2]<<endl;
    }

}

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

using namespace std;

int LCSLength(string X, string Y){
    int m = X.size();
    int n = Y.size();
    int c[m+1][n+1];
    int maxLength = 0;
    for(int i = 1; i <= m; i++) c[i][0] = 0;
    for(int j = 0; 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 if(c[i-1][j] >= c[i][j-1]) c[i][j] = c[i-1][j];
            else c[i][j] = c[i][j-1];
            maxLength = max(maxLength, c[i][j]);
        }
    }
    return maxLength;
}

int main(){
    int n;
    string X, Y;
    cin >> n;
    for(int i = 0; i < n; i++){
        cin >> X >> Y;
        cout << LCSLength(X, Y) << endl;
    }
    return 0;
}