Update 0704.二分查找.md

增加了二分查找C语言的左闭右开区间的版本,已通过leeitcode的验证
This commit is contained in:
vanyongqi
2022-09-20 18:17:56 +08:00
committed by GitHub
parent 0ba48bcc30
commit df5a6c62d5

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@ -515,7 +515,7 @@ impl Solution {
```
**C:**
```c
```c(版本一)
int search(int* nums, int numsSize, int target){
int left = 0;
int right = numsSize-1;
@ -541,6 +541,29 @@ int search(int* nums, int numsSize, int target){
return -1;
}
```
```
C (版本二)
int search(int* nums, int numsSize, int target){
int length = numsSize;
int left = 0;
int right = length;//定义target在左闭右开的区间里[left, right)
int middle = 0;
while(left < right){// left == right时区间[left, right)属于空集,所以用 < 避免该情况
int middle = left + (right - left) / 2;
if(nums[middle] < target){
//target位于(middle , right) 中为保证集合区间的左闭右开性,可等价为[middle + 1,right)
left = middle + 1;
}else if(nums[middle] > target){
//target位于[left, middle)中
right = middle ;
}else{// nums[middle] == target 找到目标值target
return middle;
}
}
//未找到目标值,返回-1
return -1;
}
```
**PHP:**
```php