The dichotomy of Java

2. Don't say much nonsense, first come to the program. Step by step look at the notes,

3. The first thing to note is that when using the dichotomy, the array must be ordered, that is, from large to small, or from smallest to largest, and cannot be unordered.

   1  Public Static intHalfsearch (int[] arr,intkey) {2             intMin,max,mid;//minimum, maximum, and median values, respectively3Min = 0;4max = Arr.length-1;5Mid = (max + min)/2;//This should be the core of the two points,6             //when key = Arr[mid] indicates that the data has been found, so the condition of the while loop is! =7              while(Arr[mid]! =key) {8                 if(Key >Arr[mid]) {9Min = mid + 1;Ten}Else if(Key <Arr[mid]) { Onemax = Mid-1; A                 } -                 //Returns-1 indicates no found -                 if(Max <min) { the                     return-1; -                 } -Mid = (max + min)/2; -             } +             //The return value for the corresponding key is worth subscript -             returnmid; +}

The dichotomy of Java