#include <cs50.h>
#include <stdio.h>
#include <string.h>

// Max number of candidates
#define MAX 9

// preferences[i][j] is number of voters who prefer i over j
int preferences[MAX][MAX];

// locked[i][j] means i is locked in over j
bool locked[MAX][MAX];
bool circle;
// Each pair has a winner, loser
typedef struct
{
    int winner;
    int loser;
} pair;

// Array of candidates
string candidates[MAX];
pair pairs[MAX * (MAX - 1) / 2];

int pair_count;
int candidate_count;

// Function prototypes

bool vote(int rank, string name, int ranks[]);
void record_preferences(int ranks[]);
void add_pairs(void);
void sort_pairs(void);
void lock_pairs(void);
void print_winner(void);
// check the graph making cycle
bool iscircle();
bool gointo(bool visited[], int to);

int main(int argc, string argv[])
{
    // Check for invalid usage
    if (argc < 2)
    {
        printf("Usage: tideman [candidate ...]\n");
        return 1;
    }

    // Populate array of candidates
    candidate_count = argc - 1;
    if (candidate_count > MAX)
    {
        printf("Maximum number of candidates is %i\n", MAX);
        return 2;
    }
    for (int i = 0; i < candidate_count; i++)
    {
        candidates[i] = argv[i + 1];
    }

    // Clear graph of locked in pairs
    for (int i = 0; i < candidate_count; i++)
    {
        for (int j = 0; j < candidate_count; j++)
        {
            locked[i][j] = false;
        }
    }

    pair_count = 0;
    int voter_count = get_int("Number of voters: ");

    // Query for votes
    for (int i = 0; i < voter_count; i++)
    {
        // ranks[i] is voter's ith preference
        int ranks[candidate_count];

        // Query for each rank
        for (int j = 0; j < candidate_count; j++)
        {
            string name = get_string("Rank %i: ", j + 1);

            if (!vote(j, name, ranks))
            {
                printf("Invalid vote.\n");
                return 3;
            }
        }

        record_preferences(ranks);

        printf("\n");
    }

    add_pairs();
    sort_pairs();
    lock_pairs();
    print_winner();
    return 0;
}

// Update ranks given a new vote
bool vote(int rank, string name, int ranks[])
{
    for (int k = 0; k < candidate_count; k++)
    {
        if (!strcmp(name, candidates[k]))
        {
            ranks[rank] = k;
            return true;
        }
    }
    return false;
}

// Update preferences given one voter's ranks
void record_preferences(int ranks[])
{
    for (int m = 0; m < candidate_count; m++)
    {
        for (int n = 0; n < candidate_count; n++)
        {
            if (m < n)
            {
                ++preferences[ranks[m]][ranks[n]];
            }
        }
    }

    return;
}

// Record pairs of candidates where one is preferred over the other
void add_pairs(void)
{
    for (int i = 0; i < candidate_count; i++)
    {
        for (int j = 0; j < candidate_count; j++)
        {
            if (preferences[i][j] == 0)
            {
                continue;
            }
            if (preferences[i][j] > preferences[j][i])
            {
                pairs[pair_count].winner = i;
                pairs[pair_count].loser = j;
                pair_count++;
            }
        }
    }
    return;
}

// Sort pairs in decreasing order by strength of victory
void sort_pairs(void)
{
    for (int i = 0; i < pair_count; i++)
    {
        for (int j = 0; j < pair_count; j++)
        {
            if (pairs[i].winner < pairs[j].winner)
            {
                pair tmp = pairs[i];
                pairs[i] = pairs[j];
                pairs[j] = tmp;
            }
        }
    }
    return;
}

// Lock pairs into the candidate graph in order, without creating cycles
void lock_pairs(void)
{
    for (int k = 0; k < pair_count; k++)
    {
        for (int i = 0; i < candidate_count; i++)
        {
        //lock pairs strarting with pair have the biggest winner
            if (pairs[k].winner == i)
            {
                locked[pairs[k].winner][pairs[k].loser] = true;
            }
        //check if creates a cycle then unlock the pair
            if (check_cycle(pairs[k].winner,pairs[k].loser))
            {
                locked[pairs[k].winner][pairs[k].loser] = false;
            }
        }
    }
    return;
}

// Print the winner of the election
void print_winner(void)
{
    // TODO
    for (int i = 0, k = 0; i < candidate_count; i++)
    {
        if (k == candidate_count)
        {
            printf("%s\n", candidates[i]);
        }

        for (int j = 0; j < candidate_count; j++)
        {
            if (!locked[j][i])
            {
                ++k;
            }
        }
    }
    return;
}
bool iscircle()
{
    bool visited[candidate_count];
    circle = false;
    return gointo(visited, 0);
}
bool gointo(bool visited[], int to)
{
// start trip form one node in the graph check if it have been visited ( Cycle )
    visited[to] = true;
    for (int n = 0; n < candidate_count; n++)
    {
        if (locked[to][n])
        {
            if (visited[n])
            {
                circle = true;
            }
            else
            {
                gointo(visited, n);
            }
            break;
        }
    }

    return circle;
}