tideman_trial

#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];

// 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);
void checkPair(int testW, int testL, int l);

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

    // Populate array of candidates
    string inputCandidate[] = { "Alice", "Bob", "Charlie"}; //new line
    candidate_count = 3; //code changed
    // 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] = inputCandidate[i]; //code changed
        printf("%s ", candidates[i]);
    }
    printf("\n");

    // 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;
            preferences[i][j] = 0;
        }
    }

    pair_count = 0;
    int voter_count = 5; // code changed

    string voteInput[5][3] = { { "Alice", "Charlie", "Bob"},
                               { "Alice", "Bob", "Charlie"},
                               { "Bob", "Charlie", "Alice"},
                               { "Bob", "Charlie", "Alice"},
                               { "Charlie", "Alice", "Bob"}};
    // 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 = voteInput[i][j];

            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[])
{
    // TODO
    for (int i = 0; i < candidate_count; i++)
    {
        if(strcmp(name, candidates[i]) == 0)
        {
            ranks[rank] = i;
            printf("Rank %i: %s\n", rank, name);
            return true;
        }
    }
    return false;
}

// Update preferences given one voter's ranks
void record_preferences(int ranks[])
{
    // TODO
    for (int i =0; i < candidate_count; i++)
    {
        for (int j = i + 1; j < candidate_count; j++ )
        {
            preferences[ranks[i]][ranks[j]]++;
        }
    }

    for (int i =0; i < candidate_count; i++)
    {
        for (int j = 0; j < candidate_count; j++ )
        {

            printf("%i  ",preferences[i][j]);
        }
        printf("\n");
    }
    return;
}

// Record pairs of candidates where one is preferred over the other
void add_pairs(void)
{
    // TODO
    pair_count = 0;
    for (int i = 0; i < candidate_count - 1; i++)
    {
        for (int j = i + 1; j < candidate_count; j++)
        {
            if (preferences[i][j] > preferences[j][i])
            {
                pairs[pair_count].winner = i;
                pairs[pair_count].loser = j;
                pair_count++;

                printf("winner: %s\n", candidates[i]);
                printf("loser: %s\n", candidates[j]);


            }
            else if (preferences[i][j] < preferences[j][i])
            {
                pairs[pair_count].winner = j;
                pairs[pair_count].loser = i;
                pair_count++;
                printf("winner: %s\n", candidates[j]);
                printf("loser: %s\n", candidates[i]);
            }
        }
    }
    printf("%i\n", pair_count);
    return;
}

// Sort pairs in decreasing order by strength of victory
void sort_pairs(void)
{
    // TODO
    pair temp;
    for (int i = 0; i < pair_count; i++)
    {
        int flag = 0;
        for (int j = 0; j < pair_count - i -1; j++)
        {
            int marginCurr = preferences[pairs[j].winner][pairs[j].loser];
            int marginNext = preferences[pairs[j + 1].winner][pairs[j + 1].loser];


            if ( marginCurr < marginNext )
            {
                temp = pairs[j];
                pairs[j] = pairs[j + 1];
                pairs[j + 1] = temp;
                flag = 1;
            }
        }
        if (flag == 0)
        {
            break;
        }
    }

    for (int i = 0; i < pair_count; i++)
    {
        printf("Rank %i:\n", i);
        printf("W: %s  L: %s\n", candidates[pairs[i].winner],candidates[pairs[i].loser]);
    }
    return;
}

// Lock pairs into the candidate graph in order, without creating cycles
void lock_pairs(void)
{
    // TODO
    for (int i = 0; i < pair_count; i++)
    {
        int winner = pairs[i].winner;
        int loser = pairs[i].loser;

        checkPair(winner, loser, loser);
    }

    for (int i = 0; i < candidate_count; i++)
    {
        for (int j = 0; j < candidate_count; j++)
        {
            if(locked[i][j])
            {
                printf("1 ");
            }
            else
            {
                printf("0 ");
            }
        }
        printf("\n");
    }
    return;
}

// Print the winner of the election
void print_winner(void)
{
    // TODO
    for (int i = 0; i < candidate_count; i++)
    {
        bool flag = true;
        for (int j = 0; j < candidate_count; j++)
        {
            if(locked[j][i])
            {
                flag = false;
            }

        }
        if(flag)
        {
            printf("%s\n", candidates[i]);
        }
    }
    return;
}

void checkPair(int testW, int testL, int l)
{
    int w = l;
    bool flag = true;
    for (int newL = 0; newL < candidate_count; newL++)
    {
        if(locked[w][newL])
        {
            if(testW == newL)
            {
                return;

            }

            else if (newL != testL)
            {

                checkPair(testW, testL, newL);
            }
        }

    if(w == testL)
    {
        locked[testW][testL] = true;
    }
    }



}