Go: package main

import (
	. "fmt"
    "math"
)

// func init() { Println("----------------------------------------") }

func main() {
    const L_MAX = 1003

	var q int
	Scanf("%d", &q)
	X := make([]string, 0, 150)
	Y := make([]string, 0, 150)
	for i := 0; i < 2 * q; i++ {
	    var tmp string
	    Scanf("%s", &tmp)

	    if i % 2 == 0 {
	        X = append(X, tmp)
	    } else {
	        Y = append(Y, tmp)
	    }
	}

    for i := 0; i < q; i++ {
        dp := make([][]int, L_MAX)
        for k, _ := range dp {
            dp[k] = make([]int, L_MAX)
        }

        x, y := X[i], Y[i]

        // init
        isXFound := false
        for c := 0; c < len(x); c++ {
            if isXFound || y[0] == x[c] {
                dp[0][c] = 1
                isXFound = true
            }
        }
        isYFound := false
        for r := 0; r < len(y); r++ {
            if isYFound || x[0] == y[r] {
                dp[r][0] = 1
                isYFound = true
            }
        }

        for r := 1; r < len(y); r++ {
            for c := 1; c < len(x); c++ {
                // dp[r][c]
                if x[c] == y[r] {
                    dp[r][c] = int(math.Max(float64(dp[r - 1][c - 1] + 1), float64(dp[r][c])))
                }

                dp[r][c] = int(math.Max(float64(dp[r][c]), math.Max(float64(dp[r - 1][c]), float64(dp[r][c - 1]))))
            }
        }
        Println(dp[len(y) - 1][len(x) - 1])

        // LCSも求めておく
        // ans := ""
        // r, c := len(y) - 1, len(x) - 1
        // for r >= 0 && c >= 0 {
        //     if y[r] == x[c] {
        //         ans = string(x[c]) + ans
        //         r--
        //         c--
        //     } else {
        //         if dp[r - 1][c] > dp[r][c - 1] {
        //             r--
        //         } else {
        //             c--
        //         }
        //     }
        // }
        // Println(ans)
    }
}

C++: #include<stdio.h>
//#include<cstdlib>
#include<cstring>

#define MAX_LEN 1000

int c[MAX_LEN+1][MAX_LEN+1]; // length of longest common subsequence

void p(){
    printf("\ntest\n");
}

int max(int a, int b){
    return a > b ? a : b;
}

int LCS(char *s1, char *s2){
    int i, j,   l, m;
    l = strlen(s1);
    m = strlen(s2);
    //printf("l:%d m:%d", l, m);
    
    for (i = 0; i < l; i++) {
        c[i][0] = 0;
     }
    
    for (j = 0; j < m; j++) {
        c[0][j] = 0;
    }
    
    
    for (i = 1; i < l+1; i++) {
        for (j = 1; j < m+1; j++) {
            if (s1[i-1] == s2[j-1]) {
                c[i][j] = c[i-1][j-1] + 1;
            }else{
                c[i][j] = max(c[i][j-1], c[i-1][j]);
            }
            //printf("c[%d][%d]:%d\n", i, j, c[i][j]);
        }
    }
    
    
    return c[l][m];
}

int main(){
    int i, n;
    char s1[MAX_LEN+1], s2[MAX_LEN+1];
    
    scanf("%d", &n);
    for (i = 0; i < n; i++) {
        scanf(" %s", s1);
        scanf(" %s", s2);
        //printf("%s\n%s\n", s1, s2);
        printf("%d\n", LCS(s1, s2));
    }
    
    return 0;
}

C++: #include<stdio.h>
#include<string.h>
#include<iostream>
#include<algorithm>
using namespace std;
int p[1001][1001]={0};
int main(){
int i,j,q,e,l,z,m,u,n;
char s[2001],c[2001];
cin>>q;
for(e=0;e<q;e++){
scanf("%s %s",s,c);
l=strlen(s);
z=strlen(c);

for(i=0;i<=l;i++){
	for(j=0;j<=z;j++){
		p[i][j]=0;
	}
}
n=0;
for(i=1;i<=z;i++){
	for(j=1;j<=l;j++){
		if(c[i-1]==s[j-1])p[j][i]=p[j-1][i-1]+1;
		else p[j][i]=p[j][i-1];
	}
}
cout<<p[l][z]<<endl;
}
return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using lint = int64_t;
#define rep(i, n) for(int i=0; i<(n); ++i)
#define all(v)    begin(v), end(v)
#define in        []{lint n; cin>>n; return n;}()


#define LCS longest_common_subsequence
int longest_common_subsequence( const string S, const string T ) {
    vector<vector<int>> dp( S.size()+1, vector<int>(T.size()+1, 0) );

    rep( s, S.size() ) {
    rep( t, T.size() ) {
        dp[s+1][t+1] = S[s] == T[t] ?
            dp[s][t] + 1 :
            max( dp[s][t+1], dp[s+1][t] );
    }
    }

    return dp[S.size()][T.size()];
}

int main() { cin.tie(0); ios::sync_with_stdio(false);
    int N = in;
    rep( _, N ) {
        string S, T; cin >> S >> T;
        cout << LCS( S, T ) << "\n";
    }
}

C++: #include <iostream>
#include <climits>
#include <string>
using namespace std;
const int MAXSEQ = 1000;
const int INFY = -INT_MAX;

string X, Y;

int max(int m, int n){
    int max = INFY;
    printf("\n");
    return max;
}
int LSCLength(void){
    int m = X.size();
    int n = Y.size();
    int c[m+1][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 = 0; i <= m; i++){
        for (int j = 0; j <= m; j++){
        */
    /*
    if (m > n){
        cout << "will change X =" <<  X << endl;
        swap(m, n);
        swap(X, Y);
        cout << "changed X =" <<  X << endl;
    }*/
    for (int i = 1; i <= m; i++){
        for (int 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] >= c[i][j-1]){
                c[i][j] = c[i-1][j];
            }else{
                c[i][j] = c[i][j-1];
            }
        }
    }
    int max = INFY;
    //printf("\n");
    /*
    for (int i = 0; i <= m; i++){
        for (int j = 0; j <= n; j++){
            printf("%d ", c[i][j]);
        if (max < c[m][i]) max = c[i][j];
        }
        printf("\n");
    }
    */
    for (int j = 1; j <= n; j++){
        if (max < c[m][j]) max = c[m][j];
    }
    return max;
}

int main(int argc, char* argv[]) {
    int n;
    cin >> n;
    for (int i = 0; i < n; i++){
        cin >> X >> Y;
        cout << LSCLength() << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define FOR(I,A,B) for(ll I = (A); I < (B); ++I)
#define POSL(x,v) (lower_bound(x.begin(),x.end(),v)-x.begin()) //xi>=v
#define POSU(x,v) (upper_bound(x.begin(),x.end(),v)-x.begin()) //xi>v
#define NUM(x,v) (POSU(x,v)-POSL(x,v))
const ll INF=1e9+7;
const ll N = 1002;
const ll M = 21;
ll q,dp[N][N];
string x,y;
vector <ll> ans;

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0);
	cin>>q;
	FOR(k,0,q){
		cin>>x>>y;
		FOR(i,0,x.size()+1){
			FOR(j,0,y.size()+1){
				dp[i][j]=0;
			}
		}
		FOR(i,0,x.size()+1){
			FOR(j,0,y.size()+1){
				if(i==0||j==0)dp[i][j]=0;
				else{
					if(x[i]==y[j])dp[i][j] = max(dp[i-1][j]+1,dp[i][j-1]+1);
					else dp[i][j] = max(dp[i-1][j],dp[i][j-1]);
				} 
			}
		}
		ans.push_back(dp[x.size()][y.size()]);
	}
	FOR(i,0,ans.size()){
		cout<<ans[i]<<endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define INF 10000
using namespace std;

int main(){
  int N; cin>>N;
  for (int i =0; i<N; i++) {
    string s1,s2; cin >> s1 >> s2;
    int s1N = s1.size();
    int s2N = s2.size();
    int dp[s1N+1][s2N+1];
    
    for(int j=0; j<=s1N; j++) dp[j][0] =0;
    for(int k=0; k<=s2N; k++) dp[0][k] =0;
  
    for(int j=1; j<=s1N; j++){
      for(int k=1; k<=s2N; k++){ 
        if(s1[j-1] == s2[k-1]) {
          dp[j][k] = dp[j-1][k-1] +1;
        } else {
          dp[j][k] = max(dp[j][k-1], dp[j-1][k]);
        }
      }
    }
    cout << dp[s1N][s2N] <<endl; 
  }
}