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<algorithm>
#include<string>

using namespace std;

int lcs (string x, string y) {

    int m, n, c[1001][1001], i, j, maxl = 0;

    m = x.size();
    n = y.size();

    x = ' ' + x;
    y= ' ' + y;

    for (i = 0; i <= m; i++) {
        c[i][0] = 0;
    }
    for (j = 1; j <= n; j++) {
        c[0][j] = 0;
    }

    for (i = 1; i <= m; i++) {
            for (j = 1; j <= n; j++) {

                if (x[i - 1] == y[j - 1]) {
                    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 () {

    int N, i;
    string x, y;

    cin >> N;

    for (i = 0; i < N i++) {
        cin >> x >> y;
        cout << lcs (x, y) << endl;

    }

    return 0;

}

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

int main(){
  int n;
  char x[1001],y[1001];
  int dp[1002][1002];
  


  //load n;
  cin >>n;
  for(int i=0;i<n;i++){
    //initialize
    for(int i=0;i<1002;i++){
      for(int j=0;j<1002;j++){
	dp[i][j]=0; 
      }
    }
    //load string
    scanf("%s",x);
    scanf("%s",y);
    //dp
    for(int j=0;j<strlen(x);j++){
      for(int k=0;k<strlen(y);k++){
	if(x[j]==y[k]){
	  dp[j+1][k+1]=dp[j][k]+1;
	}

	else{
 
	  if(dp[j][k+1]>dp[j+1][k]){
	    dp[j+1][k+1]=dp[j][k+1];
	  }

	  else{
	    dp[j+1][k+1]=dp[j+1][k];
	  }
	}
      }
    }

    //print
    cout <<dp[strlen(x)][strlen(y)]<<endl;
  }



  return 0;
}

C++: #include <iostream>

using namespace std;

int lcs(string X, string Y) {
  X = ' ' + X;
  Y = ' ' + Y;
  int memo[1010][1010];
  int maxl = 0;

  // 初期化 境界条件を考える必要がなくなる
  for (int i = 0; i < X.size(); i++) memo[i][0] = 0;
  for (int j = 0; j < Y.size(); j++) memo[0][j] = 0;

  for (int i = 1; i < X.size(); i++) {
    for (int j = 1; j < Y.size(); j++) {
      if (X[i] == Y[j]) {
        //cout << "count up!" << endl;
        memo[i][j] = memo[i-1][j-1] + 1;
      } else {
        memo[i][j] = max(memo[i-1][j], memo[i][j-1]);
      }
      maxl = max(maxl, memo[i][j]);
    }
  }
  return maxl;
}

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

C++: #include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <utility>
#include <memory>
#include <functional>
#include <deque>
#include <cctype>
#include <numeric>
#include <ctime>
#include <bitset>
#include <cctype>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <cstring>
#include <string>
#include <sstream>
#include <algorithm>
#include <iomanip>

using namespace std;

//define
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
#define dump(x)  cerr << #x << " = " << (x) << endl;

#define INF (INT_MAX/2)
#define PI (2*acos(0.0))
#define EPS (1e-8)

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

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

typedef vector<int> vint;
typedef vector<vector<int> > vvint;
typedef vector<ll> vll;
typedef vector<vector<ll> > vvll;

int dx[8] = {0, 1, 0, -1, 1, -1, 1, -1};
int dy[8] = {1, 0, -1, 0, 1, -1, -1, 1};
int dp[1001][1001];

int main(void){
  ios_base::sync_with_stdio(0);
  int N;  cin >> N;
  while(N--){
    string a, b;  cin >> a >> b;
    memset(dp, 0, sizeof(dp));
    for(int i = 0; i < a.size(); i++){
      for(int j = 0; j < b.size(); 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.size()][b.size()] << endl;
  }
  return 0; 
}

C++: #include<iostream>
#include<vector>
#include<string>
#include<algorithm>
#include<map>
#include<queue>
#include<stack>
#include<cmath>	
#include<list>
#include<set>

constexpr auto PI = 3.14159265359;

using namespace std;

int main() {
	int q;
	string x;
	string y;
	cin >> q;

	

	for (int k = 0; k < q; ++k) {
		cin >> x;
		cin >> y;
		x = ' ' + x;
		y = ' ' + y;
		vector<vector<int>> LCS(x.length() + 1, vector<int>(y.length() + 1, 0));

		for (int i = 1; i < x.length(); ++i) {
			for (int j = 1; j < y.length(); ++j) {
				if (x[i] == y[j]) {
					LCS[i][j] = LCS[i - 1][j - 1] + 1;
				}
				else {
					LCS[i][j] = max(LCS[i - 1][j], LCS[i][j - 1]);
				}
			}
		}
		cout << LCS[x.length() - 1][y.length() - 1] << endl;
	}


	return 0;
}

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

int main(){
  vector <vector<int> > dp;
  string x,y;
  int n;

  cin >> n;
  for(int times=0;times<n;times++){
    int ans =0;

    cin >> x >> y;
    dp.resize(y.size()+1);
    for(int i=0;i<=y.size();i++){
      dp[i].resize(x.size()+1);
    }

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

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

    cout << ans << endl;
  }
}