數(shù)據(jù)結(jié)構(gòu)二分查找

package?com.datastack.search;

/**

?*?二分查找

?*/

public?class?BinarySearch?{

????public?static?void?main(String[]?args)?{

????????int[]?arr?=?new?int[]{1,2,3,4,5,6,7,8,9};

????????System.out.println(binarySearch(arr,?9));

????}

????public?static?int?binarySearch(int[]?array,int?key){

????????int?low?=?0;

????????int?hight?=?array.length?-1;

????????int?middle?=?0;

????????while(low<=hight){

????????????middle=(low+hight)/2;

????????????int?value?=?array[middle];

????????????if(value>key){

????????????????hight?=?middle-1;

????????????}else?if(value<key){

????????????????low?=?middle+1;

????????????}else{

????????????????return?middle;

????????????}

????????}

????????return?-1;

????}

}