第2题:
3、二分查找算法,折半查找算法
public static int binarySearch(int[] value, int key, int begin, int end) { if (begin<=end) { int mid = (begin+end)/2; if (value[mid]==key) return mid; if (key < value[mid]) return binarySearch(value, key, begin, mid-1); return binarySearch(value, key, mid+1, end); } return -1; }