JAVA学習-4クエリアルゴリズム

1、バイナリ検索

Oの時間複雑（LOGN）

public static int erFenSearch(int key,int[] array,int low,int high) {
		int middle = (low + high) / 2;
		if(key < array[low] || key > array[high] || low>high) {
			return -1;
		}
		if(array[middle] > key) {
			high = middle-1;
			return erFenSearch(key,array,low,high);
		}else if(array[middle] < key){
			low = middle+1;
			return erFenSearch(key,array,low,high);
		}else {
			return middle;
		}
		
	}