Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 500001), 500000)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func main() {
	fp := os.Stdin
	if len(os.Args) > 1 {
		fp, _ = os.Open(os.Args[1])
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(os.Stdout)

	n := getNextInt(scanner)
	for i := 0; i < n; i++ {
		x := getNextString(scanner)
		y := getNextString(scanner)

		fmt.Fprintln(writer, lcs(x, y))
	}

	writer.Flush()
}

func lcs(x, y string) int {
	lx := len(x)
	ly := len(y)
	dp := make([][]int, lx+1)
	for i := 0; i <= lx; i++ {
		dp[i] = make([]int, ly+1)
	}
	for i := 0; i < lx; i++ {
		for ii := 0; ii < ly; ii++ {
			if x[i] == y[ii] {
				dp[i+1][ii+1] = dp[i][ii] + 1
				continue
			}
			dp[i+1][ii+1] = dp[i][ii+1]
			if dp[i+1][ii] > dp[i+1][ii+1] {
				dp[i+1][ii+1] = dp[i+1][ii]
			}
		}
	}
	return dp[lx][ly]
}

C++: #include <iostream>
#include <string>
using namespace std;
string a,b;
int la,lb;
int dp[10000][10000];

void dpf(void){
	for(int i=1;i<=la;i++){
		for(int j=1;j<=lb;j++){
			if(a[i]==b[j]){
				dp[i][j]=dp[i-1][j-1]+1;
			}
			else{
				dp[i][j]=max(dp[i-1][j],dp[i][j-1]);
			}
		}
	}	
	return ;
}
int n;

int main(void){
	cin>>n;
	
	
for(int i=0;i<n;i++){	
	cin>>a>>b;
	la=a.length();
	lb=b.length();
	a=' '+a;
	b=' '+b;
	dpf();
	cout<<dp[la][lb]<<endl;
}


}

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

int main() {
  std::string X;
  std::string Y;
  int q;
  int answers[160];
  std::cin >> q;
  
  for(int p=0; p<q; ++p) {
    std::cin >> X;
    std::cin >> Y;

    int j=0;
    int c=0;

    for(int i=0; i<X.size(); ++i) {
      for(int k=j; k<=i; ++k) {
        if(k >= Y.size()) {
          break;
        }
        if(X[i] == Y[k]) {
          c++;
          j = k+1;
          break;
        }
      }
    }

    answers[p] = c;
  }

  for(int i=0; i<q; ++i) {
    std::cout << answers[i] << std::endl;
  }

}

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

int lcs(string x,string y);

int main(){
	int n; cin>>n;
	string x,y;
	for(int i=0;i<n;i++){
		cin>>x>>y;
		cout<<lcs(x,y)<<endl;
	}
}

int lcs(string x,string y){
	int m = x.size() , n = y.size();
	x = ' '+x; y = ' '+y;
	int **c;
	c = new int*[m+1]; for(int i=0;i<=m;i++) c[i] = new int[n+1];
	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]);
			if(i==m&&j==n) return c[i][j];
		}
	}

	for(int i=0;i<=m;i++) delete [] c[i]; delete [] c;
}

C++: #include <cstdio>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <algorithm>

using namespace std;

const int kMax = 1000 + 10;

int n, m;
char a_str[kMax], b_str[kMax];
int dp[kMax];

vector<int> init_num() {
    vector<int> res;
    map<char, set<int> > table;
    for(int i = 0;i < n;++ i) {
        if(table.count(a_str[i]) > 0) table[a_str[i]].insert(i);
        else {
            set<int> s;
            s.insert(i);
            table[a_str[i]] = s;
        }
    }
    for(int i = 0;i < m;++ i) {
        if(table.count(b_str[i]) > 0) {
            for(auto it = table[b_str[i]].rbegin();it != table[b_str[i]].rend();++ it) {
                res.push_back(*it);
            }
        }
    }
    return res;
}

int solve() {
    int res = 1;
    n = strlen(a_str);
    m = strlen(b_str);
    vector<int> num = init_num();
    dp[0] = num[0];
    for(int i = 1;i < num.size();++ i) {
        if(dp[res - 1] < num[i]) dp[res ++] = num[i];
        else dp[lower_bound(dp, dp + res, num[i]) - dp] = num[i];
    }
    return res;
}

int main() {
    int q;
    scanf("%d", &q);
    while(q --) {
        scanf("%s%s", a_str, b_str);
        printf("%d\n", solve());
    }
    return 0;
}

C++: #include <bits/stdc++.h>
#include <tuple>

#define REP(i, n) for(int i=0;i<(int)(n);i++)
#define ALL(x) (x).begin(),(x).end()
const int INF = 1e9;

using namespace std;
int dp[1000][1001] = {0};

void dfs(int i, int j, string q, string b){
    int x = j;
    string tar = b.substr(x, 1);
    while(x < b.length() && q != tar){
        x++;
        tar = b.substr(x, 1);
    }
    if(i == 0 && x < b.length()){
        while(x < b.length()){
            x++;
            dp[i][x] = 1;
        }
        return;
    }
    while(x < b.length()){
        x++;
        dp[i][x] = max(dp[i-1][j] + 1, dp[i][x]);
    }
    dp[i][j] = max(dp[i][j], dp[i-1][j]);
    return;
}

int main() {
    int n; cin >> n;
    REP(k, n){
        string a, b;
        cin >> a >> b;
        REP(i, a.length()){
            string q = a.substr(i, 1);
            REP(j, b.length()+1) dfs(i, j, q, b);
        }
        cout << dp[a.length()-1][b.length()] << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> P;
typedef pair<ll, ll> Pll;
#define debug(var)  do{std::cout << #var << " : ";view(var);}while(0)
template<typename T> void view(T e){std::cout << e << std::endl;}
template<typename T> void view(const std::vector<T>& v){for(const auto& e : v){ std::cout << e << " "; } std::cout << std::endl;}
template<typename T> void view(const std::vector<std::vector<T> >& vv){ for(const auto& v : vv){ view(v); } }
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

const int MOD = 1000000007;
const int INF = 1e9;

const int mod = 1000000007;
const int inf = 1e9;
#define PI acos(-1);
int dx[4] = {1,-1,0,0};
int dy[4] = {0,0,1,-1};
int ddx[8] = {1,1,1,-1,-1,-1,0,0};
int ddy[8] = {0,1,-1,0,1,-1,1,-1};

void solve() {
    string s, t;
    cin >> s >> t;
    int sl = s.size(), tl = t.size();
    int dp[sl+1][tl+1];
    for(int i = 0; i < sl+1; i++) for(int j = 0; j < tl+1; j++) dp[i][j] = 0;
    for(int i = 0; i < sl; i++){
        for(int j = 0; j < tl; j++) {
            if(s[i] == t[j]) 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[sl][tl] << endl;
}

int main(){
    int t;
    cin >> t;
    while(t--) solve();
}

C++: #include <iostream>
#include <string>
#include <algorithm>

using namespace std;
int n;

int main(void){
    // Your code here!
    string S, T;
    int dp[1001][1001];
    cin >> n;
    for(int c = 0; c < n; c++){
        cin >> S >> T;
        
        for(int i = 0; i <= S.size(); i++){
            dp[i][0] = 0;
        }
        for(int j = 0; j <= T.size(); j++){
            dp[0][j] = 0;
        }
        
        for(int i = 0; i < S.size(); i++){
            for(int j = 0; j < T.size(); j++){
                dp[i+1][j+1] = max(dp[i][j+1], dp[i+1][j]);
                if(S[i]==T[j]) dp[i+1][j+1] = max(dp[i][j] + 1, dp[i+1][j+1]);
            }
        }
        
        cout << dp[S.size()][T.size()] << endl;
    }
}