CS50_Labs/Lab3/plurality/plurality.c

112 lines
2.3 KiB
C

#include <cs50.h>
#include <stdio.h>
#include <string.h>
// Max number of candidates
#define MAX 9
// Candidates have name and vote count
typedef struct
{
string name;
int votes;
}
candidate;
// Array of candidates
candidate candidates[MAX];
// Number of candidates
int candidate_count;
// Function prototypes
bool vote(string name);
void print_winner(void);
int main(int argc, string argv[])
{
// Check for invalid usage
if (argc < 2)
{
printf("Usage: plurality [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].name = argv[i + 1];
candidates[i].votes = 0;
}
int voter_count = get_int("Number of voters: ");
// Loop over all voters
for (int i = 0; i < voter_count; i++)
{
string name = get_string("Vote: ");
// Check for invalid vote
if (!vote(name))
{
printf("Invalid vote.\n");
}
}
// Display winner of election
print_winner();
}
// Update vote totals given a new vote
bool vote(string name)
{
for (int i = 0; i < candidate_count; i++)
{
if (strcmp(candidates[i].name, name) == 0)
{
candidates[i].votes += 1;
return true;
}
}
return false;
}
// Print the winner (or winners) of the election
void print_winner(void)
{
//array to store candidates with highest votes
int winner_index[candidate_count];
winner_index[0] = 0;
int j = 0;
//check votes of all candidates
for (int i = 1; i < candidate_count; i++)
{
//store highest seen vote candidate index
if (candidates[i].votes > candidates[winner_index[j]].votes)
{
j = 0;
winner_index[j] = i;
}
//when more candidates have the smae amount of votes, save all of them
else if (candidates[i].votes == candidates[winner_index[j]].votes)
{
j++;
winner_index[j] = i;
}
}
//prints all winners, 1 per line
for (int i = 0; i <= j; i++)
{
printf("%s\n", candidates[winner_index[i]].name);
}
return;
}