Go: ///
// File:  0528.go
// Author: ymiyamoto
//
// Created on Thu Mar 22 01:52:09 2018
//
package main

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

var S, T string
var dp [4001][4001]int

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	for {
		scanner.Scan()
		S = scanner.Text()
		if len(S) == 0 {
			return
		}

		scanner.Scan()
		T = scanner.Text()

		for i := range dp {
			for j := range dp[i] {
				dp[i][j] = 0
			}
		}

		dp[0][0] = 0
		for i := range S {
			for j := range T {
				if S[i] == T[j] {
					dp[i+1][j+1] = max(dp[i+1][j], max(dp[i][j+1], dp[i][j]+1))
				} else {
					dp[i+1][j+1] = 0
				}
			}
		}
		var m int
		for i := range dp {
			for j := range dp[i] {
				m = max(m, dp[i][j])
			}
		}
		fmt.Println(m)
	}
}

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

string str1;
string str2;
int solve(){
    int count=0;
    int m=0;
    int limit1;
    int limit2;
    int limit;
    int i, j;
    limit1 = str1.size();
    limit2 = str2.size();
    for(i=0;i<limit1-1;i++){
        for(j=0;j<i+1;j++){
            if(str1[limit1-1-i+j] == str2[j]){
                count++;
            }else{
                m = max(m, count);
                count = 0;
            }
        }
        m = max(m, count);
        count = 0;
    }
    count = 0;
    for(i=0;i<limit2;i++){
        limit = limit1+i<limit2 ? limit1 : limit2-i;
        for(j=0;j<limit;j++){
            if(str1[j] == str2[j+i]){
                count++;
            }else{
                m = max(m, count);
                count = 0;
            }
        }
        m = max(m, count);
        count = 0;
    }
    return m;
}
int main(){
    string temp;
    while(cin >> str1 >> str2){
        if(str1.size() > str2.size()){
            swap(str1, str2);
        }
        cout << solve() << endl;
    }
}

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

using namespace std;

int main()
{
	string str,str2;
	
	for(;cin >> str;)
	{
		cin >> str2 ;
		int ans=0;
		if(str.size()>str2.size())
		{
			string a;
			a=str2;
			str2=str;
			str=a;
		}
		
		for(int i=0;i<str.size();i++)
		{
			for(int j=1;i+j<str.size();j++)
			{
				string se;
				se=str.substr(i,j);
				if(str2.find(se)!=-1)
				{
					if(ans<se.size())
						ans=se.size();
				}
				else
				{
					break ;
				}
			}
		}
		cout << ans << endl;
	}
}

C++: #include<bits/stdc++.h>
using namespace std;
int ans,s1,s2,text_here,patn_here,text_len,patn_len;
string str1,str2;

int main(){

    while(cin >> str1){
            cin >> str2;

            int s1=str1.size();
            int s2=0;

        while(s1!=0 || s2<str2.size()){

            if(s1!=0){
                s1--;
            }else{
                s2++;
            }
            text_here=0;
            patn_here=0;
            text_len=str1.size();
            patn_len=str2.size();

            while(text_here<text_len && patn_here<patn_len){
                if(str1[s1+text_here]==str2[s2+patn_here]){
                    patn_here++;
                    text_here++;
                    //cout << str1[s1+text_here] << endl;
                    ans=max(patn_here,ans);
                }else{
                    text_here++;
                    patn_here=0;
                }

            }
        }
        cout << ans << endl;
        ans=0;
    }

return 0 ;
}

C++: #include <iostream>
#include <cstdio>
#include <algorithm>
#include <cmath>
#include <vector>

using namespace std;

int main(){
	
	string str1, str2;
	
	while(true){
		
		cin >> str1;
		
		if(cin.eof()){
			break;
		}
		
		cin >> str2;
		
		int ans, len;
		ans = 0;
		
		int s1, s2;
		s1 = str1.size();
		s2 = str2.size();
		
		for(int off_ = -s1; off_ < s2; off_++){
			len = 0;
			for(int j = max(0, off_); j < min(s1 + off_, s2) ; j++){
				if(str1[j - off_] == str2[j]){
					len++;
				}else{
					len = 0;
				}
				if(ans < len){
					ans = len;
				}
			}
		}
		
		printf("%d\n", ans);
		
	}
	return 0;
}

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

char A[4002],B[4002];
short int length[4000][4000];
int mmax[200],mcor = 0;
int main(){
	int i,j,lenA,lenB;
	while(cin >> A[0]){
		cin >> A+1;
		cin >> B;
		lenA = strlen(A)-1;
		lenB = strlen(B)-1;
		for(i = 0;i < lenA;i++){
			for(j = 0;j < lenB;j++){
				length[i][j] = -1;
			}
		}
		for(i = 0;i < lenA;i++){
			for(j = 0;j < lenB;j++){
				if(length[i][j] >= 0)continue;
				for(int k = 0;i+k < lenA && i+k < lenB;k++){
						if(A[i+k] != B[i+k]){
							length[i][j] = k;
							break;
						}
				}
			}
		}
		for(i = 0;i < lenA;i++){
			for(j = 0;j < lenB;j++){
				if(mmax[mcor] < length[i][j])
					mmax[mcor] = length[i][j];
			}
		}
		mcor++;
	}
	for(i = 0;i < mcor;i++){
		cout << mmax[i] << endl;
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <cmath>
#include <cstdio>
#include <functional>
#include <numeric>
#include <stack>
#include <queue>
#include <map>
#include <set>
#include <utility>
#include <sstream>
#include <complex>
#include <fstream>

using namespace std;

#define FOR(i,a,b) for(long long i=(a);i<(b);i++)
#define REP(i,N) for(long long i=0;i<(N);i++)
#define ALL(s) (s).begin(),(s).end()
#define fi first
#define se second

#define PI acos(-1.0)
#define INF 10e9+9
#define EPS 1e-10
#define MAX_N 100100
#define MAX_M 100100

typedef long long ll;
typedef pair<ll, ll> P;
typedef pair<double, double> PD;
typedef pair<string, ll> PS;
typedef vector<ll> V;
typedef pair<P, char> PC;

string s, t;
int dp[10000][10000];

int main(){
	int MAX = -1;
	cin >> s >> t;
	REP(i, s.size()){
		REP(j, t.size()){
			if (s[i] == t[j]){
				dp[i + 1][j + 1] = dp[i][j] + 1;
			}
			MAX = max(MAX, dp[i + 1][j + 1]);
		}
	}
	cout << MAX << endl;
}

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

typedef long long ll;
typedef pair<int,int> pii;
typedef pair<ll,int> plli;
typedef pair<int,pii> pipii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<vi> vvi;
typedef vector<vvi> vvvi;
typedef vector<pii> vpii;

#define rep(i,n) for (int i=0;i<(n);i++)
#define rep2(i,a,b) for (int i=(a);i<(b);i++)
#define rrep(i,n) for (int i=(n);i>0;i--)
#define rrep2(i,a,b) for (int i=(a);i>b;i--)
#define pb push_back
#define fi first
#define se second
#define all(a) (a).begin(),(a).end()

const ll mod = 1e9 + 7;
const ll INF = 1<<30;
const int dx4[4] = {1, 0, -1, 0};
const int dy4[4] = {0, 1, 0, -1};
const int dx8[8] = {1, 1, 1, 0, 0, -1, -1, -1};
const int dy8[8] = {0, 1, -1, 1, -1, 0, 1, -1};
const double pi = 3.141592653589793;


signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    string s, t;
    while (cin >> s >> t) {
        int ssize = s.length();
        int tsize = t.length();
        vector<vector<string>> ss(ssize + 1), tt(tsize + 1);
        rep(i, ssize)rep(j, ssize - i + 1) ss[j].pb(s.substr(i, j));
        rep(i, tsize)rep(j, tsize - i + 1) tt[j].pb(t.substr(i, j));
        int low = 0;
        int high = max(ssize, tsize) + 1;
        while (high - low > 1) {
            int mid = (high + low) / 2;
            bool ok = false;
            if (mid > ssize || mid > tsize) {high = mid; continue;}
            rep(i, ss[mid].size())rep(j, tt[mid].size()) {
                if (ss[mid][i] == tt[mid][j]) {
                    ok = true;
                    break;
                }
            }
            if (ok) low = mid;
            else high = mid;
        }
        cout << low << endl;
    }
}