C++ :

#include<stdio.h>
int jdz(int x)
{
    if(x>=0) return x;
    else return -x;
}
int main()
{
    int x1,x2,y1,y2,T,x;
    scanf("%d",&T);
    while(T--)
    {
        int x=0,y=0,n=0;
        scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
        x=x2-x1;
        y=y2-y1;
        if(y>0)
        {
            n=jdz(x);
            if(n==y) printf("%d\n",n);
            else if(n<y) printf("%d\n",y);
            else
            {
                if(n==1) printf("2\n");
                else
                {
                    if((n+y)%2==0) printf("%d\n",n);
                    else printf("%d\n",n+1);
                }
            }
        }
        else if(y<0)
        {
            n=jdz(x);
            y=jdz(y);
            if(n==y) printf("%d\n",n);
            else if(n<y)
            {
                if((n+y)%2==0) printf("%d\n",y);
                else printf("%d\n",y+2);
            }
            else
            {
                if(n==1) printf("2\n");
                else
                {
                    if((n+y)%2==0) printf("%d\n",n);
                    else printf("%d\n",n+1);
                }
            }
        }
        else
        {
            n=jdz(x);
            if(n%2==1) printf("%d\n",n+1);
            else printf("%d\n",n);
        }
    }
    return 0;
}