用非递归方法实现二分查找

Answer 1

--代码如下，二分查找只适用于有序数列，对其进行查找，效率非常高，不适用于无序数列

    public static int binSearch(int srcArray[], int key) {
		int mid;
		int start = 0;
		int end = srcArray.length - 1;
		while (start <= end) {
			mid = (end - start) / 2 + start;
			if (key < srcArray[mid]) {
				end = mid - 1;
			} else if (key > srcArray[mid]) {
				start = mid + 1;
			} else {
				return mid;
			}
		}
		return -1;
	}
递归的二分查找

public static int binSearch_di(int srcArray[], int start, int end, int key) {
		int mid = (end - start) / 2 + start;
		if (srcArray[mid] == key) {
			return mid;
		}
		if (start >= end) {
			return -1;
		} else if (key > srcArray[mid]) {
			return binSearch_di(srcArray, mid + 1, end, key);
		} else if (key < srcArray[mid]) {
			return binSearch_di(srcArray, start, mid - 1, key);
		}
		return -1;
	}