Single Round Match 706

MappingABC2.cpp

#include <vector>
#define TOMOD	1000000007
using namespace std;
typedef long long int ll;
class MappingABC2
{
public:
    int countStrings(vector <int> t)
    {
        int i = 0; int N = t.size();
        int n_uniques_fltr[64] = {0}, n_uniques_frtl[64] = {0};
        int last_unique_fltr[64] = {0}, last_unique_frtl[64] = {0}, last_unique = 0;
        int used_fltr[64] = {0}, used_frtl[64] = {0};
        
        n_uniques_fltr[0] = 1; last_unique_fltr[0] = -1; used_fltr[t[0]] = 1; last_unique = 0;
        for(i = 1;i < N;++i)
            if( used_fltr[t[i]] )
            {
            	n_uniques_fltr[i] = n_uniques_fltr[i-1];
            	last_unique_fltr[i] = last_unique;
            }
        	else
            {
                used_fltr[t[i]] = 1;
                n_uniques_fltr[i] = n_uniques_fltr[i-1] + 1;
                last_unique_fltr[i] = last_unique;
                last_unique = i;
            }
        n_uniques_frtl[N-1] = 1; last_unique_frtl[N-1] = -1; used_frtl[t[N-1]] = 1; last_unique = N-1;
        for(i = N-2;i >= 0;--i)
            if( used[t[i]] )
            {
            	n_uniques_frtl[i] = n_uniques_frtl[i+1];
            	last_unique_frtl[i] = last_unique;
            }
        	else
            {
                used[t[i]] = 1;
                n_uniques_frtl[i] = n_uniques_frtl[i+1] + 1;
                last_unique_frtl[i] = last_unique;
                last_unique = i;
            }
        
        ll ans = 0;
        for(i = 2;i < N-1;++i)
            if( 1 != n_uniques_fltr[i] && 1 != n_unqiues_frtl[i] )
            {
            	int center = t[i];
            	int left = 0; bool left_have_center = 0;
            	for(left = last_unique_fltr[i];-1 != left;left = last_unique_fltr[left])
                {
                    if( center == t[left] )
                        continue;
                    int le = t[left]; bool right_have_le = 0, right_have_center = 0;
                    for(int right = last_unique_frtl[i];-1 != right;right = last_unique_frtl[right])
                        if( center == t[right] )
                        {
                        	right_have_center = 1;
                        }
                        else if( t[right] == le )
                        {
                        	right_have_le = 1;
                        }
                    ans = (ans + n_unique_frtl[i+1] - right_have_le - right_have_center) % TOMOD;
                }
            }
    }
};