Go: package main

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

//Util
func nextStr() string {
	sc.Scan()
	return sc.Text()
}

func nextInt() int {
	sc.Scan()
	i, e := strconv.Atoi(sc.Text())
	if e != nil {
		panic(e)
	}
	return i
}

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

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

func absInt(a int) int {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func absFloat64(a float64) float64 {
	if a >= 0 {
		return a
	} else {
		return -a
	}
}

func minFloat64(a, b float64) float64 {
	if a > b {
		return b
	} else {
		return a
	}
}

func str2Int(s string) int {
	n, _ := strconv.Atoi(s)
	return n
}

//Main
var sc = bufio.NewScanner(os.Stdin)
var q int
var X, Y string

func lcs(X, Y string) int {
	lenX := len(X)
	lenY := len(Y)
	dp := make([][]int, lenX+1)
	for i := 0; i < lenX+1; i++ {
		dp[i] = make([]int, lenY+1)
	}

	res := 0
	for i := 1; i < lenX+1; i++ {
		for j := 1; j < lenY+1; j++ {
			if X[i-1] == Y[j-1] {
				dp[i][j] = dp[i-1][j-1] + 1
			} else {
				dp[i][j] = maxInt(dp[i-1][j], dp[i][j-1])
			}
			//fmt.Println(dp)
			res = maxInt(res, dp[i][j])
		}

	}
	return res
}

func main() {
	sc.Split(bufio.ScanWords)
	q = nextInt()

	for i := 0; i < q; i++ {
		X = nextStr()
		Y = nextStr()

		fmt.Println(lcs(X, Y))
	}
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <map>
#include <queue>
#include <numeric>
#include <climits>
using namespace std;
//using ll = long long;
//const ll mod = 1000000007;
int n, m;
string s, t;
const int n_max = 1000;
const int m_max = 1000;

int main() {
	cin >> n;
	for(int k=0; k<n; ++k){
        cin >> s >> t;
        int dp[n_max+1][m_max+1] = {0};
	for (int i = 0; i < s.size(); ++i) {
		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 + 1][j], dp[i][j + 1]);
			}
		}
	}
        cout << dp[s.size()][t.size()] << endl;
    }
	

	return 0;
}

C++: //#include "aizu.h"
#include <iostream>
#include <string>
#include <vector>

//namespace alds1_10_c{
template<class T>
T myMin(const T& arg){
	return arg;
}
template<class F, class... S>
F myMin(const F& first, const S&... second){
	F m = myMin(second...);
	if (m > first){
		return first;
	}else{
		return m;
	}
}
int f(std::string::iterator str1, const std::string& str2, const std::vector<int>& vec){
	std::vector<int> new_v;
	new_v.push_back(vec[0] + 1);
	{
		auto v = vec.begin() + 1;
		for (auto i = str2.begin(); i != str2.end(); ++i, ++v){
			if (*i == *str1){
				new_v.push_back(myMin(*v, *(v - 1), new_v.back()));
			}else{
				new_v.push_back(myMin(*v + 1, new_v.back() + 1));
			}
		}
	}
	if (*(++str1) != '\0'){
		return f(str1, str2, new_v);
	}else{
		return new_v.back();
	}
}
int main(){
	int n;
	std::cin >> n;
	for (int i = 0; i < n; ++i){
		std::string str1, str2;
		std::cin >> str1 >> str2;
		std::vector<int> vec;
    vec.push_back(0);
		for (int j = 0; j < str2.size(); ++j){
			vec.push_back(j);
		}
		std::cout << (str1.size() + str2.size() - f(str1.begin(), str2, vec)) / 2 << "\n";
	}
}
//}

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

int main(){
  int n,AC=0;
  int dp[1010][1010];
  char *A = new char[1500];
  char *B = new char[1500];

  scanf("%d",&n);
  while(_A_){
    if(AC == n)break;
    scanf("%s",A);
    scanf("%s",B);
    for(int i=0;i<1010;i++)for(int j=0;j<1010;j++)dp[i][j]=0;

    for(int i=0;i<strlen(A);i++){
      for(int j=0;j<strlen(B);j++){
	if(A[i] == B[j]){
	  dp[i+1][j+1]=dp[i][j]+1;
	}
	else{
	  if(dp[i+1][j] > dp[i][j+1]){
	    dp[i+1][j+1]=dp[i+1][j];
	  }
	  else {
	    dp[i+1][j+1] = dp[i][j+1];
	  }
	}
      }
    }
    printf("%d\n",dp[strlen(A)][strlen(B)]);
    AC++;
  }
  delete [] A;
  delete [] B;

  return 0;
}

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

using namespace std;
static const int N=1000;
int lcs(string X, string Y){
    int m=X.size();
    int n=Y.size();
    int c[N+1][N+1];
    int maxl=0;
    X=' '+X;
    Y=' '+Y;
    int i,j;
    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]);
            }
            maxl=max(maxl,c[i][j]);
        }
    }
    return maxl;
}
int main()
{
    int n;
    string s1,s2;
    cin>>n;
    for(int i=0;i<n;i++){
        cin>>s1>>s2;
        cout<<lcs(s1,s2)<<endl;
    }

    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

static const int N=1000;

int lcs(string X, string Y) {
   // lcs置き場
   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 i = 1; i <=n; i++) c[0][i] = 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(){
   int n;cin>>n;
   rep(i, n) {
      string X, Y; cin>>X>>Y;
      cout << lcs(X, Y) << endl;
   }
   return 0;
}

C++: #include "iostream"
#include "string.h"

using namespace std;

int L[1001][1001];

int lcs( char s1[], char s2[], int l1, int l2 ) {

	if (L[l1][l2] != 0)return L[l1][l2];

	if (l1 == 0 || l2 == 0) return 0;
	else if (s1[l1-1] == s2[l2-1]) L[l1][l2] = lcs(s1, s2, l1 - 1, l2 - 1) + 1;
	else {
		int lsc1 = lcs(s1, s2, l1 - 1, l2);
		int lsc2 = lcs(s1, s2, l1, l2 - 1);

		if (lsc1 > lsc2) L[l1][l2] = lsc1;
		else L[l1][l2] = lsc2;
	}

	return L[l1][l2];
}

int main() {

	int n;
	char s1[1000], s2[1000];

	cin >> n;

	int ans[150];

	for (int i = 0; i < n; i++) {
		cin >> s1;
		cin >> s2;

		ans[i] = lcs(s1, s2, strlen(s1), strlen(s2));
	}

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

	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for(int i = 0; i < (n); i++)
using namespace std;
using ll = long long;
using pii = pair<int, int>;

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;
}

int main() {
	int q;
	cin >> q;
	while (q--) {
		string x, y;
		cin >> x >> y;
		int xsz = x.size();
		int ysz = y.size();
		//vector<vector<int>> dp(xsz + 1, vector<int>(ysz + 1));
	    int dp[1001][1001] = { 0 };
		for (int i = 0; i < xsz; i++) {
			for (int j = 0; j < ysz; j++) {
				if (x[i] == y[j]) chmax(dp[i + 1][j + 1], dp[i][j] + 1);
				chmax(dp[i + 1][j + 1], dp[i][j + 1]);
				chmax(dp[i + 1][j + 1], dp[i + 1][j]);
			}
		}
		cout << dp[xsz][ysz] << endl;
	}
	return 0;
}

C++: #include<stdio.h>
#include<string.h>
int t[1002][1002];
char s[1002],st[1002],q;
int maxn(int a,int b){
return a > b ? a : b;
}

void scan(char *a , char *b){
int l = strlen(a) , r = strlen(b);
for(int i = 0 ; i < l ; i ++ ){
    for(int j = 0 ; j < r ; j ++ )
    {
        if(a[i] == b[j])t[i+1][j+1] = 1;
    }
}
}

int prin(char *a , char *b){
int l = strlen(a) , r = strlen(b);
for(int i = 1 ; i <= l ; i ++ ){
    for(int j = 1 ; j <= r ; j ++ )
    {
        if(a[i] == b[j])t[i][j] = t[i-1][j-1]+1;
        else t[i][j] = maxn(t[i-1][j],t[i][j-1]);
    }
}
return t[l][r];
}

int main(){
int n ;
scanf("%d%c",&n,&q);
while(n--){
    scanf("%s%c%s",s,&q,st);
    scan(s,st);
    printf("%d\n",prin(s,st));
}
return 0;
}