And when I do this test, what I want to do, is say I'm going to pick the middle spot, and depending on the test, if I know it's in the upper half, I'm going to set my start at the mid point and the end stays the same, if it's in the front half I'm going to keep the front the same and I'm going to change the endpoint.

如果我知道目标数可能，再比中值点大的区间里，我可能就会把开始点设为中值点,而尾点不变，如果在小的那个区间里,就保持开始点不变而把尾点设为中值点，你们可以看到这儿的代码,就是这么做的,对不对？它是怎么做的？

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