ACM Longest Repeated Sequence

Description

You are given a sequence of integers, A = a₁, a₂, ... a_n. A consecutive subsequence of A (say a_i, a_i+1 ... a_j) is called a "repeated sequence" if it appears more than once in A (there exists some positive k that a_i+k = a_i, a_i+k+1 = a_i+1, ... a_j+k = a_j) and its appearances are not intersected (i + k > j).

Can you find the longest repeated sequence in A?

Input

Line 1: n (1 <= n <= 300), the length of A.
Line 2: the sequence, a₁ a₂ ... a_n (0 <= a_i <= 100).

Output

The length of the longest repeated sequence.

Sample Input

5
2 3 2 3 2

Sample Output

2

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <cstring>
#include <string>
#include <cstdio>
using namespace std;

int main()
{
    int n;
    cin >> n;
    vector<int> arr(n);
    for(int i = 0 ; i < n; ++ i)
        cin >> arr[i];
    int len = 0,size = arr.size();
    for(int i = 0; i < size; ++i)
    {
        for(int j = i+1; j < size ; ++j)
        {
            int k = 0;
            while(i+k < j && j+k < size){
                if(arr[i+k] == arr[j+k]){
                    k++;
                }else{
                    break;
                }
            }
            len = max(k,len);
        }
    }
    cout<< len<<endl;
}