--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;
}