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] = 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 a,b;
int main(){
    while(cin >> a >> b){
        int x=0,y=0,t=1,tmp=0,ret=0,n=a.size(),m=b.size();
        while(x < n && y < m){
            if(a[x] == b[y]){
                tmp++;
                x++;
                y++;
            }else{
                ret = max(ret,tmp);
                tmp=0;
                t?x++:y++;
                t=1-t;
            }
        }
        cout << ret << endl;
    }
}

C++: #include <iostream>
#include <map>
#include <cstring>
using namespace std;
map<string,int> m;
int main(){
	string s,t;
	while(cin >> s >> t){
		int a=0,S=s.size(),T=t.size(),i,j;
		for(j=min(S,T);j>=1;j--){
			for(i=0;i<S-j;i++) m[s.substr(i,j)]++;
			for(i=0;i<T-j;i++) if(m[t.substr(i,j)]>=1) a=max(a,j);
			m.clear();
		}
		cout<<a<<endl;
	}
}

C++: #include<bits/stdc++.h>
using namespace std;
int cnt[4001][4001];
int main(){
  string str1,str2;
  while(cin >> str1){
    cin >> str2;
    int len1 = str1.size();
    int len2 = str2.size();
    str1 = ' ' + str1;
    str2 = ' ' + str2;
    for(int i=1;i<=len1;i++){
      cnt[i][0] = 0;
    } 
    for(int i=1;i<=len2;i++){
      cnt[0][i] = 0;
    }
    int ret = 0;
    for(int i=1;i<=len1;i++){
      for(int j=1;j<=len2;j++){
	if(str1[i] == str2[j]){
	  cnt[i][j] = cnt[i-1][j-1] + 1;
	}
	else {
	  cnt[i][j] = 0;
	}
	ret = max(ret,cnt[i][j]);
      }
    }
    cout << ret << endl;
  }	
}

C++: #include <bits/stdc++.h>
#define PB push_back
#define MP make_pair
#define REP(i,n) for (int i=0;i<(n);i++)
#define FOR(i,a,b) for(int i=(a);i<(b);i++)
#define ALL(a) (a).begin(),(a).end()
int INF=1e9;
int MOD=1000000007;
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
double EPS = 1e-10;
const int mod=1e9+7;
int dp[4000][4000];
int main(){
  string s,t;
  while(cin>>s>>t){
    int ans=0;
    REP(i,s.size()){
      REP(j,t.size()){
        if(s[i]==t[j]){
          if(i==0||j==0)dp[i][j]=1;
          else dp[i][j]=dp[i-1][j-1]+1;
        }
        ans=max(ans,dp[i][j]);
      }
    }
    cout<<ans<<endl;
  }
}

C++: #include<iostream>
#include<string>
#include<algorithm>
#include<map>
#include<set>
#include<utility>
#include<vector>
#include<cmath>
#include<cstring>
#include<cstdio>
#include<time.h>
#define loop(i,a,b) for(int i=a;i<b;i++) 
#define rep(i,a) loop(i,0,a)
#define pb push_back
#define mp make_pair
#define all(in) in.begin(),in.end()
const double PI=acos(-1);
const double EPS=1e-10;
using namespace std;
typedef long long ll;
typedef vector<int> vi;
int main(){
	string a,b;
	while(cin>>a>>b){
		int n=a.size(),m=b.size();
		vector<vector<int> >dp(n+1,vector<int>(m+1));
		loop(i,1,n+1)loop(j,1,m+1){
			if(a[i-1]==b[j-1])dp[i][j]=dp[i-1][j-1]+1;
		}
		int ma=0;
		rep(i,n)rep(j,m)ma=max(ma,dp[i+1][j+1]);
		cout<<ma<<endl;
	}
}

C++: //JOI 0528 Common Sub-String
#include <iostream>
#include <string>
#include <algorithm>
using namespace std;
int main() {
	while(cin){
		string s, t; int roop1=0, save=0, ans = 0;
		cin>>s;
		cin>>t;
		if(s==/0){
		break;
		}
	for (int i = 0; i<s.size(); i++){
		for (int j = 0; j<t.size(); j++){
			if (s[i] == t[j]){
				roop1 = 0;
				save= 0;
				while (1){
					if (s[i + roop1] == 0 || t[j + roop1] == 0){
						break;
					}
					else{
						if (s[i + roop1] == t[j + roop1]){
							save += 1;
							roop1++;
						}
					else if (s[i + roop1] != t[j + roop1]){
							ans=max(ans,save);
							break;
						}
					}
				}
			}
		}
	}
	cout<<ans<<endl;
	}
	
	return 0;
}

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;
}