[Leetcode] Search Insert Position (Java)

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

给定一个有序数组A[]，给定一个数字target，将target插入有序数组A[]中，返回插入位置。（数组A[]中无重复）

二分查找，然后判断下位置

public class SearchInsertPosition {
public int searchInsert(int[] A, int target) {
int res = 0;
int low = 0;
int high = A.length - 1;
while (low <= high) {
int med = low + ((high - low) >> 1);
if (A[med] == target) {
res = med;
break;
} else if (A[med] < target) {
low = med + 1;
} else {
high = med - 1;
}
}
if(res==0){
if(low==A.length)
res=A.length;
else if(A[low]>=target)
res=low;
else
res=low+1;
}
return res;
}
public static void main(String[] args) {
int[] A = {1};
int target = 2;
System.out.println(new SearchInsertPosition().searchInsert(A, target));
}
}