Daily Temperatures问题及解法

问题描述：

Given a list of daily temperatures, produce a list 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 temperatures = [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].

问题分析：

利用stack存储温度，遇到第一个较大的温度就记录下来。

过程详见代码：

class Solution {public:    vector<int> dailyTemperatures(vector<int>& temperatures) {        int n = temperatures.size();vector<int> res(n, 0);stack<pair<int, int>> st;for (int i = 0; i < n; i++){while (!st.empty()){if (st.top().first < temperatures[i]){res[st.top().second] = i - st.top().second;st.pop();}else {break;}}st.push(pair<int, int>(temperatures[i], i));}return res;    }};