monitoring process incomplite

#include<stdio.h>
struct monitoring
{
    int x;
    int y;
};
int main()
{
    int n,m,i,j,k,l,a,b,max,v=0,T;
    scanf("%d",&T);
    while(v++,T-- &&scanf("%d",&n)==1)
    {

        m=n*2;
        int arr2[m];
        struct monitoring arr[m],temp;
        for(i=0; i<m; i++)
        {
            scanf("%d",&arr[i].x);
            if(i%2==0)
            {
                arr[i].y=1;
            }
            else
            {
                arr[i].y=-1;

            }
        }
        for(j=0; j<m; j++)
        {
            for(k=j+1; k<m; k++)
            {
                if(arr[j].x>arr[k].x)
                {
                    temp=arr[j];
                    arr[j]=arr[k];
                    arr[k]=temp;

                }
                else if(arr[j].x==arr[k].x && arr[j].y<arr[k].y)
                {
                    temp=arr[j];
                    arr[j]=arr[k];
                    arr[k]=temp;
                }

            }
        }


        for(a=0; a<m; a++)
        {
            arr[a+1].y=arr[a].y+arr[a+1].y;
        }
        max=arr[0].y;
        for(i=1; i<m; i++)
        {
            if(max<arr[i].y)
            {
                max=arr[i].y;
            }
        }
        printf("Case %d: %d\n",v,max);

    }

    return 0;
}