个人记录-LeetCode 35. Search Insert Position

问题：

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.

You may assume no duplicates in the array.

Here are few examples.

[1,3,5,6], 5 → 2
[1,3,5,6], 2 → 1
[1,3,5,6], 7 → 4
[1,3,5,6], 0 → 0

代码示例：

问题比较简单，二分法就可以解决，注意细节即可。

public class Solution {
public int searchInsert(int[] nums, int target) {
if (nums == null || nums.length < 1) {
return 0;
}

if (nums.length == 1) {
if (nums[0] >= target) {
return 0;
}

return 1;
}

return getIndex(nums, target, 0, nums.length-1);
}

private int getIndex(int[] nums, int target, int begin, int end) {
int middle = (begin + end) / 2;

if (nums[middle] == target) {
return middle;
} else if (nums[middle] > target){
if (begin < middle - 1) {
return getIndex(nums, target, begin, middle - 1);
} else {
return judgeThenGetResult(nums, begin, target);
}
} else {
if (middle + 1 < end) {
return getIndex(nums, target, middle + 1, end);
} else {
return judgeThenGetResult(nums, end, target);
}
}
}

private int judgeThenGetResult(int[] nums, int index, int target) {
if (nums[index] >= target) {
return index;
} else {
return index + 1;
}
}
}