Help me in solving CPPCC96 problem

My issue

can someone explain this question . the name is “journey of the night”

My code

#include <bits/stdc++.h>
using namespace std;

int main(int argc, char const *argv[])
    int t;
    cin >> t;

    while (t > 0)
        int x1,y1,x2,y2;
        cin >> x1 >> y1 >> x2 >> y2;
        if(x1 ==x2 || y1 == y2){
    return 0;

Learning course: Medium C++ puzzles
Problem Link: CodeChef: Practical coding for everyone

this question states that u have to find whether your knight which is at (x1,y1) can go to the cell (x2,y2) in exactly 100 steps or not.
Focus on exactly 100 not more nor less.