Just wanted to share this cause I found this easier

include

include

int main() { int shelfbook[100][100], count=0, count2=0; int total_number_of_shelves; scanf("%d", &total_number_of_shelves);

int total_number_of_queries;
scanf("%d", &total_number_of_queries);

while (total_number_of_queries>0)
{   
    total_number_of_queries--;
    int type_of_query;
    scanf("%d", &type_of_query);

    if (type_of_query == 1) 
    {
        int x, y; 

        for(count; count>0; count--)
        { shelfbook[x][count]=shelfbook[x][count-1];}

        scanf("%d %d", &x, &y);
        shelfbook[x][0]= y;

        count++;

    } 
    else if (type_of_query == 2) 
    {
        int x, y;
        scanf("%d %d", &x, &y);
        printf("%d",shelfbook[x][y]);
    } 
    else if (type_of_query == 3)
    {
        int x;
        scanf("%d", &x);


        for (int y=0; y<100; y++)
        {
            if (shelfbook[x][y]!=0)
            { count2++;}
        }
        printf("%d\n", count2);
    }
}

return 0;

}