Go: package main

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

// define
var (
	sc = bufio.NewScanner(os.Stdin)
)

func bordersInt(in_map [][]int, invalid int) [][]int{
	H, W := len(in_map), len(in_map[0])
	out_map := make([][]int, H+2)
	for h:=0; h<H+2; h++ {
		out_map[h] = make([]int, W+2)
		for w:=0; w<W+2; w++ {
			out_map[h][w] = invalid
		}
	}
	for h:=0; h<H; h++{
		for w:=0; w<W; w++{
			out_map[h+1][w+1] = in_map[h][w] 
		}
	}
	return out_map
}

func bordersString(in_map [][]string, invalid string) [][]string{
	H, W := len(in_map), len(in_map[0])
	out_map := make([][]string, H+2)
	for h:=0; h<H+2; h++ {
		out_map[h] = make([]string, W+2)
		for w:=0; w<W+2; w++ {
			out_map[h][w] = invalid
		}
	}
	for h:=0; h<H; h++{
		for w:=0; w<W; w++{
			out_map[h+1][w+1] = in_map[h][w] 
		}
	}
	return out_map
}

func scanIntLine(len int) []int{
	arr := make([]int, len)
	for i:=0; i<len; i++{
		sc.Scan()
		tmp, err := strconv.Atoi(sc.Text())
		if err == nil{
			arr[i] = tmp
		}
	}
	return arr
}

func scanStringLine(len int) []string{
	arr := make([]string, len)
	for i:=0; i<len; i++{
		sc.Scan()
		arr[i] = sc.Text()
	}
	return arr
}

func scanIntSplit(len int) []int{
	arr := make([]int, len)
	sc.Scan()
	for i, v := range strings.Split(sc.Text(), " "){
		tmp, err := strconv.Atoi(v)
		if err == nil{
			arr[i] = tmp
		}
	}
	return arr
}

func maxInt(args... int) int{
	sort.Ints(args)
	return args[len(args)-1]
}

func main(){
	buf := make([]byte, 0)
    sc.Buffer(buf, 1000000009)
	var n int 
	fmt.Scan(&n)
	dp := make([][]int, 1003)
	for i:=0; i<1003; i++ {
		dp[i] = make([]int, 1003)
	}
	input_lines := scanStringLine(2*n)
	for i:=0; i<n; i++ {
		S, T := input_lines[2*i], input_lines[2*i+1]
		lenS, lenT := len(S), len(T)
		for i:=1; i<lenS+1; i++ {
			for j:=1; j<lenT+1; j++ {
				if S[i-1] == T[j-1] {
					dp[i][j] = maxInt(dp[i-1][j-1]+1, dp[i-1][j], dp[i][j-1])
				} else {
					dp[i][j] = maxInt(dp[i-1][j], dp[i][j-1])
				}
			}
		}
		fmt.Println(dp[lenS][lenT])
	}
}

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 a, b;

    cin >> N;

    for(i = 0 ; i < N ; i++) {
        cin >> a;
        cin >> b;
        cout << lcs(a, b) << endl;
    }

    return 0;
}

C++: /*
** Longest Common Subsequence
*/

# include <cstdio>
# include <cstring>
# include <algorithm>
using namespace std;

const int MAX = 1000 + 5;

char s1[MAX], s2[MAX];
int c[MAX][MAX];

int lcs() {
    int m = strlen(s1);
    int n = strlen(s2);
    c[0][0] = 0;
    int maxl = 0;
    for (int i = 0; i < m; i++) {
        c[i][0] = 0;
    }
    for (int i = 0; i < n; i++) {
        c[0][i] = 0;
    }

    for (int i = 0; i < m; i++) {
        for (int j = 0; j < n; j++) {
            if (s1[i] == s2[j]) {
                c[i][j] = c[i - 1][j - 1] + 1;
            }
            else {
                c[i][j] = max(c[i][j - 1], c[i - 1][j]);
            }
            maxl = max(maxl, c[i][j]);
        }
    }

    return maxl;
}

void solve() {
    int n;
    scanf("%d", &n);
    while (n--) {
        scanf("%s %s", s1, s2);
        printf("%d\n", lcs());
    }
}

int main() {
    // freopen("infile", "r", stdin);
    // freopen("outfile", "w", stdout);
    solve();
    return 0;
}

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

int main(void){
    int Q;
    cin >> Q;
    
    for(int q = 0;q < Q;q++){
        string x,y;
        cin >> x >> y;
        
        int dp[x.size()+1][y.size()+1];
        for(int i = 0;i < x.size()+1;i++){
            for(int j = 0;j < y.size()+1;j++){
                dp[i][j] = 0;
            }
        }
        
        for(int i = 0;i < x.size();i++){
            for(int j = 0;j < y.size();j++){
                if(x[i] == y[j]){
                    dp[i+1][j+1] = max(dp[i+1][j+1],dp[i][j]+1);
                }
                dp[i+1][j+1] = max(dp[i+1][j+1],dp[i][j+1]);
                dp[i+1][j+1] = max(dp[i+1][j+1],dp[i+1][j]);
            }
        }
        cout << dp[x.size()][y.size()] << endl;
    }
}

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

#define N 1000

int lcs(string x, string y) {
  int i, j, m, n, lcs[N+1][N+1];
  
  m = x.length();
  n = y.length();
  // indexずれを補正
  x = ' ' + x;
  y = ' ' + y;
  
  // 初期値
  for (i = 0; i < m + 1; i++) lcs[i][0] = 0;
  for (j = 0; j < n + 1; j++) lcs[0][j] = 0;
  // 漸化式
  for (i = 1; i <= m; i++) {
    for (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-1][j], lcs[i][j-1]);
    }
  }

  return lcs[m][n];
}

int main() {
  int i, q, lcs_arr[N];
  string x, y;

  cin >> q;

  for (i = 0; i < q; i++) {
    cin >> x;
    cin >> y;
    lcs_arr[i] = lcs(x, y);
  }    

  for (i = 0; i < q; i++) cout << lcs_arr[i] << endl;
    
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cstring>
#include <fstream>

#define SMAX 1000
#define QMAX 150

using namespace std;

int main()
{
  int q;
  cin >> q;
  
  char X[SMAX], Y[SMAX];
  int LCS[SMAX+1][SMAX+1] = {0};
  int Anwser[QMAX];
  for(int i = 0; i<q; i++) {
    scanf("%s",X);
    scanf("%s",Y);
    int size_X = strlen(X);
    int size_Y = strlen(Y);
    for(int j = 0; j <= size_X; j++) LCS[j][0] = 0;
    for(int j = 0; j <= size_Y; j++) LCS[0][j] = 0;

    for(int j = 1; j <= size_X; j++) {
      for(int k = 1; k <= size_Y; k++) {
	if(X[j-1] == Y[k-1]) LCS[j][k] = LCS[j-1][k-1] + 1;
	else LCS[j][k] = max(LCS[j-1][k], LCS[j][k-1]);
      }
    }
    Anwser[i] = LCS[size_X][size_Y];
  }

  for(int i = 0; i<q; i++) cout << Anwser[i] << endl;

  return 0;
}

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

static const int N = 100;

int main(){
	int n, p[N + 1], m[N + 1][N + 1];
	cin >> n;
	for(int i=1;i<=n;i++){
		cin >> p[i - 1] >> p[i];
	}

	for(int i=1;i<=n;i++) m[i][i] = 0;
	for(int l=2;l<=n;l++){
		for(int i=1;i<=n-l+1;i++){
			int j=i+l-1;
			m[i][j] = (1 << 21);
			for(int k=i;k<=j-1;k++){
				m[i][j] = min(m[i][j], m[i][k] + m[k+1][j] + p[i-1] * p[k] * p[j]);
			}
		}
	}

	cout << m[1][n] << endl;

	return 0;
}

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