题目描述:
Suppose a sorted array is rotated at some pivot unknown to you beforehand. (i.e., might become ). Find the minimum element. You may assume no duplicate exists in the array.
这道题《剑指offer》上有原题,直接上代码
solution:
int findMin(vector<int>& nums) {
int start = ;
int end = nums.size() - ;
while (start < end)
{
if (nums[start] < nums[end])
break;
int mid = start + (end - start) / ;
if (nums[mid] >= nums[start])
start = mid + ;
else
end = mid;
}
return nums[start];
}
参考:https://leetcode.com/discuss/13389/compact-and-clean-c-solution
上述程序没有考虑数组中存在相同元素这一情况。如果考虑的话,代码需要修改。
solution:
int findMin(vector<int>& nums) {
int start = ;
int end = nums.size() - ;
while (start < end)
{
if (nums[start] < nums[end])
break;
int mid = start + (end - start) / ;
if (nums[mid] > nums[end])
start = mid + ;
else if (nums[mid] < nums[end])
end = mid;
else
{
++start;
--end;
}
}
return nums[start];
}
最后附上一个《剑指offer》上的解法:
int MinInOrder(vector<int> &nums, int start, int end)
{
int min = nums[start];
for (int i = ; i < nums.size(); ++i)
{
if (nums[i] < min)
min = nums[i];
}
return min;
} int findMin(vector<int>& nums) {
int start = ;
int end = nums.size() - ;
while (start < end)
{
if (nums[start] < nums[end])
break;
int mid = start + (end - start) / ; if (nums[mid] == nums[start] && nums[mid] == nums[end])
{
return MinInOrder(nums, start, end);
}
if (nums[mid] >= nums[start])
start = mid + ;
else
end = mid;
}
return nums[start];
}
PS:
《剑指offer》上的解法不一定是最好的!!!