13300번 방 배정

https://www.acmicpc.net/problem/13300

#include <iostream>
#include <queue>
#include <stack>
#include <cstdio>
#include <vector>
#include <cstring>
#include <string>
#include <math.h>
#include <algorithm>
#include <map>
 
using namespace std;
 
int main(void)
{
    int N = 0, K = 0, room = 0;
    int S = 0, Y = 0;
    int student[2][7] = { 0, };
 
    memset(student, 0, sizeof(student));
 
    scanf("%d %d", &N, &K);
 
    for (int i = 0; i < N; i++)
    {
        scanf("%d %d", &S, &Y);
 
        ++student[S][Y];
 
        //아래 2줄은 내가 실수했던 부분
        //if (student[S][Y] == 1) ++room;
        //else if (student[S][Y] > K) ++room;
    }
 
    for (int i = 0; i <= 1; i++)
    {
        for (int j = 1; j <= 6; j++)
        {
            room += (student[i][j] + K - 1) / K;
        }
    }
 
    printf("%d\n", room);
 
    return 0;
}