LC739. 每日温度
vector<int> dailyTemperatures(vector<int>& temperatures)
{
int size = temperatures.size();
vector<int> result(size, 0);
vector<int> sta;
sta.push_back(0);
for (int i = 1; i < size; ++i)
{
while (sta.empty() != true)
{
int temp = sta.back();
if (temperatures[i] > temperatures[temp])
{
result[temp] = i - temp;
sta.pop_back();
}
else
break;
}
sta.push_back(i);
}
return result;
}
LC496. 下一个更大元素Ⅰ
使用一个unordered_map哈希表对nums1做映射（key：下标元素，value：下标）
vector<int> nextGreaterElement(vector<int>& nums1, vector<int>& nums2)
{
int size = nums1.size();
vector<int> result(size, -1);
vector<int> sta;
sta.push_back(nums2[0]);
unordered_map<int, int> umap;
for (int i = 0; i < size; ++i)
{
umap[nums1[i]] = i;
}
for (int i = 1; i < nums2.size(); ++i)
{
if (nums2[i] > sta.back())
{
while (sta.empty() != true && nums2[i] > sta.back())
{
int temp = sta.back();
if (umap.find(temp) != umap.end())
{
result[umap[temp]] = nums2[i];
}
sta.pop_back();
}
}
sta.push_back(nums2[i]);
}
return result;
}