2～5

import java . util . Arrays ; import java . util . Scanner ; public class Example2_5{ public static void main ( String args []){ int start =0, end , middle ; int a []={12,45,67,89,123,-45,67}; int N = a . length ; int minIndex =-1; for ( int i=0; i <N-1; i ++){ minIndex = i ; for ( int j =i+1; j <=N-1; j ++){ if ( a [ j ]< a [ minIndex ])

if ( number > a [ middle ]) start = middle ; else if ( number < a [ middle ]) end = middle ; middle =( start + end )/2; count ++; if ( count > N /2) break ; if ( count > N /2) System . out . printf (＂왕 d 不在数组中．\ n ", number ); else System , out . printf (＂왕 d 在数组中．\ n ", number );