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>
#include<unordered_set>
#include<unordered_map>
#include <algorithm> 
#include <iostream>
#include <string>
#include <cmath>
using namespace std;
#define ll long long
#define rep(i, n) for (ll i = 0; i < (n); i++)
#define FOR(i,a,b) for(ll i=(a);i<(b);i++)
#define FORR(i,a,b)for(ll i=(a);i<=(b);i++)
#define repR(i,n) for(ll i=n;i>=0;i--)
#define all(v)(v).begin(),(v).end()
#define rall(v)(v).rbegin(),(v).rend()
#define F first
#define S second
#define pb push_back
#define pu push
#define COUT(x) cout<<(x)<<endl
#define PQ priority_queue<ll>
#define PQR priority_queue<ll,vector<ll>,greater<ll>>
#define YES(n) cout << ((n) ? "YES" : "NO"  ) << endl
#define Yes(n) cout << ((n) ? "Yes" : "No"  ) << endl
#define mp make_pair
#define maxs(x,y) (x = max(x,y))
#define mins(x,y) (x = min(x,y))
#define sz(x) (ll)(x).size()
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
const ll MOD = 1000000007LL;
const ll INF = 1LL << 60;
using vll = vector<ll>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vvll = vector<vll>;
using vstr = vector<string>;
using pll = pair<ll, ll>;
using vc = vector<char>;
using vvc = vector<vc>;
template<class T> inline bool chmax(T& a, T b) { 
if (a < b) { a = b; return true; } return false; 
}
template<class T> inline bool chmin(T& a, T b) {
 if (a > b) { a = b; return true; } return false; 
 }
ll dx[4]={0,1,0,-1};
ll dy[4]={1,0,-1,0};
ll dp[1005][1005];
ll res(string a,string b){
  memset(dp,0,sizeof(dp));
  rep(i,sz(a))rep(j,sz(b)){
    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]);
  }
  return dp[sz(a)][sz(b)];
}
int main(){
  ll q;
  cin>>q;
  rep(i,q){
    string a,b;
    cin>>a>>b;
    COUT(res(a,b));
  }
}

C++: #include<stdio.h>
#include<string.h>
    
int LCS(char *X, char *Y){
  int i,j,m,n,c[1001][1001];
  m = strlen(X);
  n = strlen(Y);
      
  for(i=0; i<m; i++){
    c[i][0] = 0;
  }
  for(j=0; j<n; j++){
    c[0][j] = 0;
  }
    
  for(i=1;i<m+1;i++){
    for(j=1;j<n+1;j++){
      if (X[i-1]==Y[j-1]) 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];
    }
  }
  return c[i-1][j-1];
}
    
int main(){
  int i, q;
  char X[1001], Y[1001];
      
  scanf("%d", &q);
  for(i=0; i<q; i++){
    scanf("%s", X);
    scanf("%s", Y);
    printf("%d\n", LCS(X, Y));
    
  }
  return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
int main(){
  string  a,b;
  long n=0,i,c=0;
  cin>>a>>b;
  for(i=0;i<a.size();i++)if(a[i]==b[c])if(++n)c++;
  cout<<n<<endl;
}

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

int DP[1010][1010];

int main() {
  int n;
  cin >> n;
  for (auto t=0; t<n; t++) {
    string A, B;
    cin >> A >> B;
    int LA = (int) A.size();
    int LB = (int) B.size();
    fill(&DP[0][0], &DP[0][0]+1010*1010, 0);
    for (auto i=-1; i<LA; i++) {
      for (auto j=-1; j<LA; j++) {
        if (i == -1 || j == -1) {
          DP[i+1][j+1] = 0;
        } else if (A[i] == B[j]) {
          DP[i+1][j+1] = 1 + DP[i][j];
        } else {
          DP[i+1][j+1] = max(DP[i+1][j], DP[i][j+1]);
        }
      }
    }
    cout << DP[LA][LB] << endl;
  }
}

C++: #include<iostream>
#include<string>
#include<algorithm>
using namespace std;
int main(){
    int n,i,j;string s,t;cin >> n;
    while(cin >> s >> t){
        int dp[s.size()+1][t.size()+1] = {};
        for(i=1;i<=s.size();i++){
            for(j=1;j<=t.size();j++){
                if(s[i-1]==t[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[s.size()][t.size()] << endl;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;

#define rep(i, n) for (int i=0; i<(n); ++i)
using ll = long long;
using P = pair<int, int>;

const int MAX = 1003;
int dp[MAX][MAX];

int lcs(string x, string y) {
  int m = x.length();
  int n = y.length();
  x = ' ' + x;
  y = ' ' + y;
  rep(i,m+1) dp[i][0] = 0;
  rep(i,n+1) dp[0][i] = 0;

  int ans = 0;
  for (int i=1; i<=m; i++) {
    for (int j=1; j<=n; j++) {
      if (x[i] == y[j]) dp[i][j] = dp[i-1][j-1] + 1;
      else dp[i][j] = max(dp[i-1][j], dp[i][j-1]);
      //printf("[*] %d %d %d\n", i, j, dp[i][j]);
      ans = max(ans, dp[i][j]);
    }
  }

  return ans;
}

int main() {
  int n;
  cin >> n;
  string x, y;
  vector<int> ans;
  rep(i,n) {
    cin >> x;
    cin >> y;
    ans.push_back(lcs(x, y));
  }

  rep(i,ans.size()) cout << ans[i] << endl;
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

int lcs(string a,string b){
  int c[1001][1001];
  int m=a.size(),n=b.size();
  int mx=0;
  a=' '+a;
  b=' '+b;
  for(int i=1;i<=m;i++){
    for(int j=1;j<=n;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]);
      }
      mx=max(mx,c[i][j]);
    }
  }
  return mx;
}


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