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package algorithm;

public class BinarySearch {

public static void main(String[] args) {

int[] data = { 0, 1, 2, 4, 6, 8, 9 };

int index = binarySearch(3, data);

System.out.println(index);

//int srcArray[] = { 3, 5, 11, 17, 21, 23, 28, 30, 32, 50, 64, 78, 81,95, 101 }; // 15个数

//System.out.println(binSearch(srcArray, 0, srcArray.length - 1, 81));

}

static int binarySearch(int value, int[] data) {

int smallIndex = 0;

int bigIndex = data.length;

System.out.println("123 " + data[(smallIndex + bigIndex) / 2]);

while (data[(smallIndex + bigIndex) / 2] > value) {

System.out.println(111);

bigIndex = (smallIndex + bigIndex) / 2;

if (data[(smallIndex + bigIndex) / 2] == value)

return (smallIndex + bigIndex) / 2;

}

/* while (data[(smallIndex + bigIndex) / 2] < value) {

System.out.println(222);

smallIndex = (smallIndex + bigIndex) / 2;

if (data[(smallIndex + bigIndex) / 2] == value)

return (smallIndex + bigIndex) / 2;

}*/

return -1;

}

int binary(int value, int[] data) {

return -1;

}

//回调的做法

public static int binSearch(int srcArray[], int start, int end, int value) {

//int mid = (end - start) / 2 + start;

int mid = (end + start) / 2 ;

if (srcArray[mid] == value) {

return mid;

}

if (start >= end) {

return -1;

} else if (value > srcArray[mid]) {

return binSearch(srcArray, mid + 1, end, value);

} else if (value < srcArray[mid]) {

return binSearch(srcArray, start, mid - 1, value);

}

return -1;

}

}