二分查找 69. Sqrt(x)(二分查找) 35. Search Insert Position(二分查找) 34. Search for a Range 33. Search in Rotated Sorted Array(二分查找) 81. Search in Rotated Sorted Array II 74. Search a 2D Matrix(二分查找,剑指offer 1) 50. Pow(x, n)(二分查找)