Go: package main

import "fmt"

func initialize_grid(width int,height int)[][]int{
	var grid [][]int
	for i:=0;i<height+1;i++{
		var grid_row  []int
		for j:=0;j<width+1;j++{
			grid_row = append(grid_row,0)
		}
		grid = append(grid,grid_row[:])
	}
	return grid
}

func ma(x int,y int)int{
	if x >= y{
		return x
	}else{
		return y
	}
}

func main()  {
	//Take input
	var num int
	var st1,st2 string
	var string_pairs [][]string
	fmt.Scan(&num)
	for i:=0;i<num;i++{
		var string_pair []string
		fmt.Scan(&st1)
		fmt.Scan(&st2)
		string_pair = append(string_pair,st1,st2)
		string_pairs = append(string_pairs,string_pair)
	}
	//DP
	//initialize grid
	for i:=0;i<num;i++{
		string_1 := string_pairs[i][0]
		string_2 := string_pairs[i][1]

		dp := initialize_grid(len(string_2),len(string_1))

		for j:=1;j<len(string_1)+1;j++{
			for k:=1;k<len(string_2)+1;k++{
				if string_1[j-1] == string_2[k-1]{
					dp[j][k] = dp[j-1][k-1] + 1
				}else{
					dp[j][k] = ma(dp[j-1][k],dp[j][k-1])
				}
			}
		}
		fmt.Println(dp[len(string_1)][len(string_2)])
	}
}

C++: #include <iostream>
#include <string>
#include <algorithm>
#include <cstdlib> 
using namespace std;
static const int N = 1000;

int lcs(string X,string Y){
	int **c=(int **)malloc(sizeof(int *)*1001);
	for(int i=0;i<1001;i++){
		c[i]=(int *)malloc(sizeof(int)*1001);
	}
	int m=X.size();
	int n=Y.size();
	int maxl=0;
	X=' '+X;
	Y=' '+Y;
	c[0][0]=0;
	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;
}

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

using namespace std;

int main(void)
{
    int q;
    char x[1001], y[1001];
    int table[1001][1001];
    
    cin >> q;
    for (int i = 0; i < q; i++) {
        cin >> x >> y;
        int xl = strlen(x), yl = strlen(y);

        for (int i = 0; i < xl; i++)
            for (int j = 0; j < yl; j++)
                if (x[i] == y[j])
                    table[i+1][j+1] = 1 + table[i][j];
                else
                    table[i+1][j+1] = max(table[i][j+1], table[i+1][j]);

        cout << table[xl][yl] << endl;
    }

    return 0;
}

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

int dp[1001][1001];
int main() {
    int q;
    cin>>q;
    int ans[150] = {0};
    for (int i = 0; i < q; ++i) {
        memset(dp, 0, sizeof(dp));
        string x, y;
        cin>>x>>y;
        int xlen = x.length();
        int ylen = y.length();
        for(int ix = 0; ix < xlen; ++ix) {
            for(int iy = 0; iy < ylen; ++iy) {
                if (x[ix] == y[iy]) {
                    dp[ix + 1][iy + 1] = max(max(dp[ix][iy] + 1, dp[ix + 1][iy]), dp[ix][iy+1]);
                } else {
                    dp[ix + 1][iy + 1] = max(dp[ix + 1][iy], dp[ix][iy+1]);
                }
            }
        }
        ans[i] = dp[xlen][ylen];
    }

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

}

C++: #include<bits/stdc++.h>
#define REP(i,n) for(long long i=0;i<n;++i)
#define FOR(i,a,b) for(long long i=a;i<b;++i)
using namespace std;
int main(){
    int q;
    scanf("%d",&q);
    string x,y;
    REP(i,q){
        cin>>x>>y;
        int dp[x.size()+1][y.size()+1];
        fill(dp[0],dp[x.size()],-1);
        REP(j,x.size()+1) dp[j][0]=0;
        REP(j,y.size()+1) dp[0][j]=0;
        FOR(j,1,x.size()+1){
            FOR(k,1,y.size()+1){
                if(x[j-1]==y[k-1]) dp[j][k]=dp[j-1][k-1]+1;
                else dp[j][k]=max(dp[j][k-1],dp[j-1][k]);
            }
        }
        printf("%d\n",dp[x.size()][y.size()]);
    }
    return 0;
}

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

#define N 1000

int lcs(std::string x, std::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 = 0; i <= m; i++) c[i][0] = 0;
	for (int i = 0; i <= m; 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] = std::max(c[i - 1][j], c[i][j - 1]);
			maxl = std::max(maxl, c[i][j]);
		}
	}
	return maxl;
}

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

C++: #include <iostream>
#include <vector>
#include <string>
#include <cmath>
#include <set>
#include <algorithm>
#include <array>
#include <complex>
#include <utility>
#include <map>
#include <inttypes.h>

int LCS(std::string s, std::string t){
    int n, m, c[1001][1001] = {0};
    n = s.size();
    m = t.size();
    int maxlen = 0;
    for(int i = 1; i <= n; i++){
        c[i][0] = 0;
    }
    for(int i = 1; i <= m; i++){
        c[0][i] = 0;
    }
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= m; j++){
            if(s[i - 1] == t[j - 1]){
                c[i][j] = c[i - 1][j - 1] + 1;
            }
            else{
                c[i][j] = std::max(c[i - 1][j], c[i][j - 1]);
            }
            maxlen = std::max(maxlen, c[i][j]);
        }
    }
    return maxlen;
}
int main(){
    int N;

    std::cin >> N;
    std::string s1, s2;
    for(int i = 0; i<N; i++){
        std::cin >> s1 >> s2;
        std::cout << LCS(s1, s2) << std::endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(ll i=0; i<n; i++)
typedef long long ll;
typedef long double ld;
typedef long long unsigned int llu;
ll MOD = 1000000007;
ll INF = 1000000009;

/*
Xのi番目とYのj番目までのLCS
*/

int lcs[1010][1010];

void solve(){

    int q;
    cin >> q;
    vector<int> v;
    rep(i,q){
        string s,t;
        cin >> s;
        cin >> t;
        rep(i,1010){
            rep(j,1010){
                lcs[i][j]=0;
            }
        }
        for(int i=0; i<s.length(); i++){
            for(int j=0; j<t.length(); j++){
                if(s[i]==t[j]) lcs[i+1][j+1]=lcs[i][j]+1;
                else lcs[i+1][j+1]=max(lcs[i+1][j], lcs[i][j+1]);
            }
        }
        v.emplace_back(lcs[s.length()][t.length()]);
    }

    for(auto e: v){
        cout << e << endl;
    }
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  return 0;
}

C++: #include <algorithm>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <deque>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <vector>

using namespace std;

#define pb push_back

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<i_i, int> p_i;
typedef vector<int> vi;
typedef vector<vector<int> > vvi;
template<class T> using vv=vector<vector< T > >;

int main() {
  int t;
  cin >> t;
  vi results;
  for (int dataset = 0 ; dataset < t ; dataset++) {
    string a, b;
    cin >> a;
    cin >> b;
    vvi len(a.length()+1, vi(b.length()+1, 0));
    for (int ia = 0 ; ia < a.length() ; ia++) {
      for (int ib = 0 ; ib < b.length() ; ib++) {
        if (a[ia] == b[ib]) {
          len[ia+1][ib+1] = len[ia][ib]+1;
        } else {
          len[ia+1][ib+1] = max(len[ia+1][ib], len[ia][ib+1]);
        }
      }
    }
    results.pb(len[a.length()][b.length()]);
  }

  for (int it = 0 ; it < t ; it++) {
    printf("%d\n", results[it]);
  }

  return 0;
}