That sounds like two separate and different questions.
1.) Would you murder an innocent person if it meant saving the lives of about one hundred people?
2.) Would you take the life of that person, even if that person wasn’t willing to sacrifice themselves?
In Scenario #1, no. The guilt albeit hard to live with, really lies in the lap of the ones doing the killing.
In Scenario #2, if it was a person that was terminally ill and they begged me to take their life because they were suffering and wouldn’t end it via suicide, then I would consider it. If the question is meant to represent that the other 100 will die whether the one individual kills themself or I do it, I still feel fairly confident that I would not be the murderer. Even if the 100 people are killed and the one person and I survive, I would hope that we could eventually look upon this as a manipulative mind game out of our control and eventually work through this horrific experience.