Leetcode每日一题：Daily Temperatures（递减栈）

Given a list of daily temperatures T, return a list such that, for each day in the input, tells you how many days you would have to wait until a warmer temperature. If there is no future day for which this is possible, put 0 instead.

For example, given the list of temperatures T = [73, 74, 75, 71, 69, 72, 76, 73], your output should be [1, 1, 4, 2, 1, 1, 0, 0].

Note: The length of temperatures will be in the range [1, 30000]. Each temperature will be an integer in the range [30, 100].

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/daily-temperatures

维护一个递减栈，温度从下到上越来越小才行。

class Solution {
public:
    vector<int> dailyTemperatures(vector<int>& T) {
        int n = T.size();
        vector<int> ans(n);
        stack<int> s;
        for(int i=0;i<n;i++){
            while(!s.empty()&&T[i]>T[s.top()]){
                int j =s.top();
                s.pop();
                ans[j]= i-j;
            }
            s.push(i);
        }
        return ans;
        
    }
};