704. 二分查找

class Solution {
public:int search(vector<int>& nums, int target) {int left = 0, right = nums.size() - 1;while (left <= right) {int mid = left + (right - left) / 2;if (nums[mid] == target) {return mid;} else if (nums[mid] < target) {left = mid + 1;} else if (nums[mid] > target) {right = mid - 1;}}return -1;}
};

278. 第一个错误的版本

// The API isBadVersion is defined for you.
// bool isBadVersion(int version);class Solution {
public:int firstBadVersion(int n) {int left = 1, right = n;while (left <= right) {int mid = left + (right - left) / 2;if (!isBadVersion(mid)) {left =  mid + 1; } else {right = mid - 1;}}return left;}
};

977. 有序数组的平方

class Solution {
public:vector<int> sortedSquares(vector<int>& nums) {int len = nums.size();int left = 0, right = len - 1;vector<int> res(len);for (int i = len - 1; i >= 0; --i) {int leftVal = nums[left] * nums[left];int rightVal = nums[right] * nums[right];if (leftVal > rightVal) {res[i] = leftVal;left++;} else {res[i] = rightVal;right--;}}return res;}
};</