Go: package main

import "fmt"

func main() {
	var nPairs int
	fmt.Scanln(&nPairs)

	var a, b string
	for i := 0; i < nPairs; i++ {
		fmt.Scanln(&a)
		fmt.Scanln(&b)
		fmt.Println(lcsSize(a, b))
	}
}

func lcsSize(sa, sb string) int {
	dp := make([][]int, len(sa)+1)
	for i := 0; i <= len(sa); i++ {
		dp[i] = make([]int, len(sb)+1)
	}

	for a := 1; a <= len(sa); a++ {
		for b := 1; b <= len(sb); b++ {
			if sa[a-1] == sb[b-1] {
				dp[a][b] = dp[a-1][b-1] + 1
			} else {
				dp[a][b] = max(dp[a][b-1], dp[a-1][b])
			}
		}
	}

	return dp[len(sa)][len(sb)]
}

func max(a, b int) int {
	if a > b {
		return a
	}
	return b
}

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

using namespace std;

int q;
char X[1000], Y[1000];
int dp[1001][1001];

int main(void) {

    scanf("%d", &q);

    for (int i = 0; i < q; ++i) {
        scanf("%s %s", X, Y);
        int xlen = strlen(X), ylen = strlen(Y);
        for (int x = 0; x < xlen; ++x) {
            for (int y = 0; y < ylen; ++y) {
                if (X[x] == Y[y]) {
                    dp[x + 1][y + 1] = dp[x][y] + 1;
                }
                else {
                    if (dp[x + 1][y] > dp[x][y + 1]) {
                        dp[x + 1][y + 1] = dp[x + 1][y];
                    }
                    else {
                        dp[x + 1][y + 1] = dp[x][y + 1];
                    }
                }
            }
        }
        printf("%d\n", dp[xlen][ylen]);
    }

    return 0;
}

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

void solve(){
	string a,b;
	cin >> a >> b;
	int dp[1001][1001];
	memset(dp,0,sizeof(dp));
	for(int i=0;i<=a.size();i++){
		for(int j=0;j<=b.size();j++){
			if(i > 0)
				dp[i][j] = max(dp[i][j],dp[i-1][j]);
			if(j > 0)
				dp[i][j] = max(dp[i][j],dp[i][j-1]);
			if(i > 0 && j > 0)
				dp[i][j] = max(dp[i][j],dp[i-1][j-1] + (a[i-1] == b[j-1] ? 1 : 0));
		}
	}
	cout << dp[a.size()][b.size()] << endl;
}
int main(void) {
	int q;
	cin >> q;
	for(int i=0;i<q;i++){
		solve();
	}
	return 0;
}

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

int LCS(const string &a, const string &b) {
	vector<vector<int>> dp(a.size() + 1, vector<int>(b.size() + 1, 0));
	for (int i = 0; i <= a.size(); i++) {
		for (int j = 0; j <= b.size(); j++) {
			if (i > 0 && j > 0) {
				if (a[i - 1] == b[j - 1]) {
					dp[i][j] = max(dp[i][j], dp[i - 1][j - 1] + 1);
				}
				else {
					dp[i][j] = max(dp[i][j], dp[i - 1][j - 1]);
				}
				dp[i][j] = max(dp[i][j], dp[i][j - 1]);
				dp[i][j] = max(dp[i][j], dp[i - 1][j]);
			}
			else if (i > 0) {
				dp[i][j] = max(dp[i][j], dp[i - 1][j]);
			}
			else if (j > 0) {
				dp[i][j] = max(dp[i][j], dp[i][j - 1]);
			}
		}
	}
	return dp[a.size()][b.size()];
}

int main()
{
	int n;
	string X, Y;
	cin >> n;
	while (n--) {
		cin >> X >> Y;
		cout << LCS(X, Y) << endl;
	}
	return 0;
}

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

#define MAX 1000

int lcs(string X, string Y) {
    int c[MAX+1][MAX+1];
    int m = X.size();
    int n = Y.size();
    int i, j;
    int maxlen = 0;
    X = " " + X;
    Y = " " + Y;

    for (i = 1 ; 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] == Y[j]) {
                c[i][j] = c[i-1][j-1] + 1;
            }else {
                c[i][j] = max(c[i][j-1], c[i-1][j]);
            }
            maxlen = max(maxlen, c[i][j]);
        }
    }
    return maxlen;
}

int main (void) {
    int N, i;
    string x, y;

    cin >> N;

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

C++: #include <iostream>
#include <cstdio>
#include <string>
#include <algorithm>
#include <utility>
#include <cmath>
#include <vector>
#include <queue>
#include <set>
#include <map>
#define rep(i, n) for(int i = 0; i < n; i++)
using namespace std;
typedef long long ll;
const ll mod = 1000000007;

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

    int ans[q];

    rep(k, q) {
        string x, y;
        cin >> x >> y;

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

        int dp[m+1][n+1] = {};  // dp[i][j] : xのi文字目までとyのj文字目までのLCSの長さ(i, jは0-index)

        rep(i, m) {
            rep(j, n) {
                if(x[i] == y[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]);
                }
            }
        }

        ans[k] = dp[m][n];
    }

    rep(i, q) {
        cout << ans[i] << "\n";
    }

    return 0;
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>
#include <list>
#include <set>
#include <map>
#include <queue>
#include <stack>
#include <cctype>
#include <cassert>
#include <climits>
#include <string>
#include <bitset>
#include <cfloat>
#include <random>
#include <iomanip>
#include <unordered_set>
using namespace std;
typedef long double ld;
typedef long long int ll;
typedef unsigned long long int ull;
typedef vector<int> vi;
typedef vector<char> vc;
typedef vector<bool> vb;
typedef vector<double> vd;
typedef vector<string> vs;
typedef vector<ll> vll;
typedef vector<pair<int,int> > vpii;
typedef vector<pair<ll,ll> > vpll;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<vc> vvc;
typedef vector<vs> vvs;
typedef vector<vll> vvll;
typedef map<int,int> mii;
typedef set<int> si;
#define rep(i,n) for(ll i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define arep(i,v) for(auto i : v)
#define irep(it, stl) for(auto it = stl.begin(); it != stl.end(); it++)
#define drep(i,n) for(int i = (n) - 1; i >= 0; --i)
#define fin(ans) cout << (ans) << '\n'
#define STLL(s) strtoll(s.c_str(), NULL, 10)
#define mp(p,q) make_pair(p, q)
#define pb(n) push_back(n)
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define Sort(a) sort(a.begin(), a.end())
#define Rort(a) sort(a.rbegin(), a.rend())
#define MATHPI acos(-1)
#define fi first
#define se second
constexpr int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
constexpr int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
template <class T> inline bool chmax(T& a,T b){if(a<b){a=b;return 1;} return 0;}
template <class T> inline bool chmin(T& a,T b){if(a>b){a=b;return 1;} return 0;}
template <class T> inline void dump(T &v){irep(i, v){cout<<*i<<((i==--v.end())?'\n':' ');}}
inline string getline(){string s; getline(cin,s); return s;}
inline void yn(const bool b){b?fin("yes"):fin("no");}
inline void Yn(const bool b){b?fin("Yes"):fin("No");}
inline void YN(const bool b){b?fin("YES"):fin("NO");}
struct io{io(){ios::sync_with_stdio(false);cin.tie(0);}};
const int INF = INT_MAX;
constexpr ll LLINF = 1LL<<60;
constexpr ll MOD = 1000000007;
constexpr ld EPS = 1e-11;

int lcs(string &s, string &t) {
    vvi dp(s.size() + 1, vi(t.size() + 1));
    
    for(int i = 0; i < s.size(); i++) {//LCS
        for(int j = 0; j < t.size(); j++) {
            if(s[i] == t[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]);
            }
        }
    }
    return dp[s.size()][t.size()];
}

int main() {
    
    int n;
    cin>>n;
    rep(i,n){
        string s,t;
        cin>>s>>t;
        fin(lcs(s,t));
    }
}