1 uint16 FindPosition(uint8 arr[], uint16 length, uint8 target)
2 {
3 uint16 low = 0;
4 uint16 high = length - 1;
5 uint16 closest_position = 0xFFFF;
6
7 if (target < arr[0] || target > arr[length - 1])
8 {
9 return 0xFFFF; // target不在数组范围内
10 }
11
12 while (low <= high)
13 {
14 uint16 mid = low + (high - low) / 2;
15
16 if (arr[mid] == target)
17 {
18 return mid;
19 }
20 else if (arr[mid] < target)
21 {
22 closest_position = mid; // 更新最接近且小于target的位置
23 low = mid + 1;
24 }
25 else
26 {
27 high = mid - 1;
28 }
29 }
30
31 return closest_position; // 返回最接近且小于target的位置
32 }
1 int main(int argc, char *argv[])
2 {
3 uint8 arr[] = {1, 3, 5, 7, 10, 11, 13,17, 20, 23, 29,32,40,49};
4 uint16 length = sizeof(arr) / sizeof(arr[0]);
5 uint8 target = 14;
6
7 uint16 position = FindPosition(arr, length, target);
8
9 if (position != 0xFFFF)
10 {
11 printf("Closest position less than target found at position: %d\n", position);
12 }
13 else
14 {
15 printf("Target not in range\n"); //result:6
16 }
17 //system("pause");
18 return 0;
19 }
