package android.util
class ContainerHelpers 實現(xiàn)二分法的幫助類（循環(huán)實現(xiàn)法）
在 Arrays.binarySearch()也可找到示例
// This is Arrays.binarySearch(), but doesn't do any argument validation.
static int binarySearch(int[] array, int size, int value) {
int lo = 0;
int hi = size - 1;
while (lo <= hi) {
final int mid = (lo + hi) >>> 1;
final int midVal = array[mid];
if (midVal < value) {
lo = mid + 1;
} else if (midVal > value) {
hi = mid - 1;
} else {
return mid; // value found
}
}
return ~lo; // value not present
}
static int binarySearch(long[] array, int size, long value) {
int lo = 0;
int hi = size - 1;
while (lo <= hi) {
final int mid = (lo + hi) >>> 1;
final long midVal = array[mid];
if (midVal < value) {
lo = mid + 1;
} else if (midVal > value) {
hi = mid - 1;
} else {
return mid; // value found
}
}
return ~lo; // value not present
}
