Go: package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
)

// I/O
type Scanner struct {
	sc *bufio.Scanner
}

func NewScanner() *Scanner {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 1024), int(1e+9))
	return &Scanner{sc}
}

func (s *Scanner) nextStr() string {
	s.sc.Scan()
	return s.sc.Text()
}

func (s *Scanner) nextInt() int {
	i, e := strconv.Atoi(s.nextStr())
	if e != nil {
		panic(e)
	}
	return i
}

func (s *Scanner) nextFloat() float64 {
	f, e := strconv.ParseFloat(s.nextStr(), 64)
	if e != nil {
		panic(e)
	}
	return f
}

func (s *Scanner) nextRuneSlice() []rune {
	return []rune(s.nextStr())
}

func (s *Scanner) nextIntSlice(n int) []int {
	res := make([]int, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextInt()
	}
	return res
}

func (s *Scanner) nextFloatSlice(n int) []float64 {
	res := make([]float64, n)
	for i := 0; i < n; i++ {
		res[i] = s.nextFloat()
	}
	return res
}

// Arithmetic
func max(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m < i {
			m = i
		}
	}
	return m
}

func min(nums ...int) int {
	m := nums[0]
	for _, i := range nums {
		if m > i {
			m = i
		}
	}
	return m
}

func abs(x int) int {
	if x > 0 {
		return x
	}
	return -x
}

func pow(x, y int) int {
	res := 1
	for i := 0; i < y; i++ {
		res *= x
	}
	return res
}

func ceil(a, b int) int {
	if a%b == 0 {
		return a / b
	} else {
		return a/b + 1
	}
}

// Sort
type RuneSlice []rune

func (a RuneSlice) Len() int           { return len(a) }
func (a RuneSlice) Less(i, j int) bool { return a[i] < a[j] }
func (a RuneSlice) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }

// Main
func main() {
	sc := NewScanner()
	wtr := bufio.NewWriter(os.Stdout)
	Q := sc.nextInt()
	for q := 0; q < Q; q++ {
		X, Y := sc.nextStr(), sc.nextStr()
		xLen, yLen := len(X), len(Y)
		dp := make([][]int, xLen+1)
		for i := 0; i <= xLen; i++ {
			dp[i] = make([]int, yLen+1)
		}
		for x := 0; x <= xLen; x++ {
			for y := 0; y <= yLen; y++ {
				if x == 0 || y == 0 {
					dp[x][y] = 0
				} else if X[x-1] == Y[y-1] {
					dp[x][y] = dp[x-1][y-1] + 1
				} else {
					dp[x][y] = max(dp[x-1][y], dp[x][y-1])
				}
			}
		}
		fmt.Fprintln(wtr, dp[xLen][yLen])
	}

	wtr.Flush()
}

C++: #include <bits/stdc++.h>
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 = 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 {
                c[i][j] = max(c[i - 1][j], c[i][j - 1]);
            }
            maxl = max(maxl, c[i][j]);
        }
    }

    return maxl;
}

int main(void)
{
    string X, Y;
    int n; cin >> n;

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

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

string s, t;
int dp[100][100];

void solve() {
    cin >> s >> t;
    for (int i = 0; i < s.size(); i++) {
        for (int j = 0; j < t.size(); j++) {
            dp[i][j] = (i < 1 || j < 1 ? 0 : dp[i-1][j-1]) + (s[i] == t[j] ? 1 : 0);
            int a = (i < 1 ? 0 : dp[i-1][j]);
            int b = (j < 1 ? 0 : dp[i][j-1]);
            dp[i][j] = max(dp[i][j], max(a, b));
        }
    }

    cout << dp[s.size()-1][t.size()-1] << endl;
}

int main() {
    int n;
    cin >> n;
    while (n--) solve();

    return 0;
}

C++: #include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <ctime>
#include <cstring>
#include <functional>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <vector>

#define REP(i,n)   for (int i = 0; i < (n); ++i)
#define SORT(a)    sort((a).begin(), (a).end());
#define UNIQ(a)    SORT(a);(a).erase(unique((a).begin(), (a).end()), (a).end());
#define FIND(a,x)  find((a).begin(), (a).end(), (x)) != (a).end()
#define REVERSE(a) reverse((a).begin(), (a).end());

using namespace std;
using ll = long long;
using P = pair<int,int>;

const int MOD = 1000000007; // 10^9 + 7

int lcs(string x, string y) {
  int m = x.size(), n = y.size();
  int dp[m + 1][n + 1]; memset(dp, 0, sizeof(dp));

  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]);

  return dp[m][n];
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  srand((unsigned)time(NULL));

  int t; cin >> t;
  REP(i, t) {
    string x, y; cin >> x >> y;

    cout << lcs(x, y) << endl;
  }
}

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

int main(){
  int q;
  cin>>q;
  while(q--){
    string x,y;
    cin>>x>>y;
    vector<vector<int>> dp(x.size()+1,vector<int>(y.size()+1,0));
    
    for(int xi=0;xi<x.size();++xi){
      for(int yi=0;yi<y.size();++yi){
        if(x[xi]==y[yi]){
          dp[xi+1][yi+1]=dp[xi][yi]+1;
        }else{
          if (dp[xi+1][yi]>dp[xi][yi+1]){
            dp[xi+1][yi+1]=dp[xi+1][yi];
          }else{
            dp[xi+1][yi+1]=dp[xi][yi+1];
          }
        }
      }
    }
    int ans=dp[x.size()][y.size()];
    cout << ans << endl;
  }
}

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

// Dynamic Programming - LCS

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);

    int q;
    cin >> q;

    for (int _ = 0; _ < q; ++_) {
        string s1, s2;
        cin >> s1 >> s2;

        const int s1_size = s1.size();
        const int s2_size = s2.size();
        vector<vector<int>> dp(s1_size + 1);
        for (int i = 0; i < s1_size + 1; ++i) dp[i].resize(s2_size + 1, 0);

        for (int i = 0; i < s1_size; ++i) {
            for (int j = 0; j < s2_size; ++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]);
            }
        }
        cout << dp[s1_size][s2_size] << "\n";
    }

    cout << flush;
    return 0;
}

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