200 tall building, 150 long rope

I found a Web page with many smart questions. I have seen most of the questions. This blog has also been introduced before. However, there is a particularly interesting question that makes my eyes shine, and I have never seen such problems before. I don't know if you have seen it. Share with you.
You are trapped on the roof of a 200 tall building. You have a 150-meter-long rope and a Swiss Army knife in your hand. There is an iron hook in the place where you are standing. When you look downstairs, you find that there is a metal bracket in the middle of the building, that is, a 100-meter-tall location, with another hook on it. How can you use these things to safely reach the ground?

Answer: Cut the rope into two segments: 50 meters and 100 meters. Tie one end of the 50-meter rope to the hook on the roof, and make a small ring on the other end. Let the 100-meter-long rope pass through the ring, and then tie its two ends together to form a rope ring. Climb along the rope to the ground, cut the 100-meter-long rope and take it back. Then, tie one end to the hook and climb along the rope to the ground.