first_last_in_array
first_last_in_array.cpp 源码
// 在排序数组中查找元素的第一个和最后一个位置
#include "iostream"
#include "vector"
using namespace std;
class Solution {
public:
// 线性查找
vector<int> searchRange1(vector<int>& nums, int target) {
vector<int> res{-1, -1};
for (int i = 0; i < nums.size(); i++) {
if (nums[i] == target) {
if (i == 0 || nums[i - 1] != target) {
res[0] = i;
}
if (i == nums.size() - 1 || nums[i + 1] != target) {
res[1] = i;
}
}
}
return res;
}
// 二分查找
vector<int> searchRange2(vector<int>& nums, int target) {
vector<int> res{-1, -1};
int low = 0, high = nums.size() - 1;
while(low <= high) {
int mid = low + (high - low) / 2;
if(nums[mid] < target) {
low = mid + 1;
} else if(nums[mid] > target) {
high = mid - 1;
} else {
if(nums[low] == target && nums[high] == target) {
return {low, high};
}
if(nums[low] != target) {
low++;
}
if(nums[high] != target) {
high--;
}
}
}
return res;
}
};
你可能感兴趣的文章
0
赞
热门推荐
-
2、 - 优质文章
-
3、 gate.io
-
6、 golang
-
7、 openharmony