SWEA 4371. 항구에 들어오는 배 (C++)

#include <stdio.h>

int N;
int happyday[5001];
int visited[5001];
int main()
{
    int tc;
    scanf("%d", &tc);
    for (int t = 1; t <= tc; t++)
    {
        int cnt = 0;
        scanf("%d", &N);
        for (int i = 0; i < N; i++)
        {
            scanf("%d", &happyday[i]);
        }

        int num = 0;
        for (int i = 1; i < N; i++)
        {
            if (visited[i])
                continue;

            num = happyday[i] - happyday[0];
            for (int j = i + 1; j < N; j++)
            {
                if (!visited[j] && (happyday[j] - happyday[i]) % num == 0)
                    visited[j] = true;
            }
            cnt++;
        }

        printf("#%d %d\n", t, cnt);
        for (int i = 0; i < N; i++)
        {
            visited[i] = false;
        }
    }
    return 0;
}