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<iostream>
#include<string>
#include<algorithm>
using namespace std;
static const int MAX=1000;

int LCS(string X, string Y) {
    int i, j, maxl=0;
    int C[MAX+1][MAX+1];

    int X_len = X.size();
    int Y_len = Y.size();
    X = ' ' + X;
    Y = ' ' + Y;
    for (i=0; i<=X_len; i++) C[i][0]=0;
    for (j=1; j<=Y_len; j++) C[0][j]=0;

    for (i=1; i<=X_len; i++) {
        for (j=1; j<=Y_len; j++) {
            if (X[i]==Y[j]) {
                C[i][j]=C[i-1][j-1]+1;
                maxl = max(C[i][j], maxl);
            } else C[i][j]=max(C[i-1][j], C[i][j-1]);
        }
    }

    return maxl;
}

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

    return 0;
}

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

using namespace std;
int main(int argc, const char * argv[]) {
    int q, i, m, n, sl1, sl2;
    cin >> q;
    vector<string> strlist;
    string str, str1, str2;
    for(i = 0;i < q;i++){
        cin >> str;
        strlist.push_back(str);
        cin >> str;
        strlist.push_back(str);
    }
    
    //start
    for(i = 0;i < q*2;i += 2){
        str1 = strlist[i];
        sl1 = str1.length();
        str2 = strlist[i+1];
        sl2 = str2.length();
        int dp[sl1+1][sl2+1];
        for(m = 0;m <= sl2;m++){
            dp[0][m] = 0;
        }
        for(m = 0;m <= sl1;m++){
            dp[m][0] = 0;
        }
        for(m = 1;m <= sl1;m++){
            for(n = 1;n <= sl2;n++){
                if(str1[m] == str2[n]){
                    dp[m][n] = dp[m-1][n-1] + 1;
                }else{
                    dp[m][n] = max(dp[m-1][n], dp[m][n-1]);
                }
            }
        }
        m = sl1;
        n = sl2;
        printf("%d\n", dp[m][n]);
        for(m = 1;m <= sl1;m++){
            for(n = 1;n <= sl2;n++){
                printf(" %d ", dp[m][n]);
            }
            printf("\n");
        }
        printf("\n");
        
    }
    return 0;
}

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



int lcs(string X,string Y){
	
	int c[720][720];
int m = X.size();
int n = Y.size();
int max1 = 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]);
		}
		max1 = max(max1,c[i][j]);
		}
	} 
	return max1;
}



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

C++: //
//  main.cpp
//  ALDS1_10_C Longest Common Subsequence
//
//  Created by Kang on 2020/8/13.
//  Copyright © 2020 Kang. All rights reserved.
//

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

char X[1001];
char Y[1001];

int LCS(int m, int n) {
    int c[1001][1001];
    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 = 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 {
                c[i][j] = max(c[i][j - 1], c[i - 1][j]);
            }
            
        }
    }
    return c[m][n];
}

int main(int argc, const char * argv[]) {
    int q;
    scanf("%d", &q);
    for (int i = 0; i < q; i++) {
        scanf("%s", X);
        scanf("%s", Y);
        printf("%d\n", LCS((int)strlen(X), (int)strlen(Y)));
    }
    return 0;
}

C++: #define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
#define len(n) (int)n.length()
#define pb push_back
#define ll long long
#define make_pair mkp
#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define ALL(v) (v).begin(), (v).end()
#ifdef DBGPRT
#define dbg(n) cerr << "//" << #n << ":" << n <<endl
#else
#define dbg(n) ;
#endif
typedef pair<ll, ll> LLARR;
#define INF 999999999
const double PI = 3.1415926535897932384626433832795;

ll lcs(string s1, string s2)
{
	int m = len(s1);
	int n = len(s2);
	s1 = ' '+s1;
	s2 = ' '+s2;
	int (*mat)[1001];
	mat = new int[1001][1001];
	REP(i, m)
	{
		mat[i][0] = 0;
	}
	REP(i, n)
	{
		mat[0][i] = 0;
	}
	int maxx = 0;
	FOR(i, 1, m+1)
	{
		FOR(j, 1, n+1)
		{
			if (s1[i] == s2[j])
				mat[i][j] = mat[i-1][j-1] + 1;
			else
				mat[i][j] = max(mat[i][j-1], mat[i-1][j]);
			maxx = max(maxx, mat[i][j]);
		}
	}
	delete[] mat;
	return maxx;
}
int main()
{
	ios::sync_with_stdio(false);

	int n;
	cin >> n;
	REP(i, n)
	{
		string s1;
		cin >> s1;
		string s2;
		cin >> s2;
		cout << lcs(s1, s2) << endl;
	}
	return 0;
}

C++: #include <iostream> 
#include <cstring> 
using namespace std;
int c[1001][1001];

int lcs(string x, string y)
{
    int maxl = 0;
    int m = x.length(), n = y.length();
 
    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 = 0; i < m; i++)
    {
        for (int j = 0; j < n; j++)
        {
            if (x[i] == y[j])
            { 
                if(i==0 || j==0) c[i][j] = 1;
                else c[i][j] = c[i-1][j-1] + 1; 
            }else
            {
                if(i==0 || j==0) c[i][j] = 0;
                else c[i][j] = max(c[i][j-1], c[i-1][j]);
            }
            maxl = max(maxl, c[i][j]);
        } 
    } 
    return maxl;
}

int main()
{
    
    //freopen("in1.txt","r",stdin);
    string x,y;
    int q;
    cin>>q;
    while(q--)
    {
        cin>>x>>y;
        int ans = lcs(x, y);
        cout<<ans<<endl;
    }
    return 0;
}