Description

Tag：Stack, Hash Table

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].

Solution

从后向前，将大值压入栈中，在压栈过程中，将小值pop出去，然后依次查找即可。

type ele struct {     index int     temperature int} var stack []elevar top = -1func dailyTemperatures(T []int) []int {    size := len(T)    stack = make([]ele, size)    result := make([]int, size)    for i:= size -1; i>=0;i-- {        result[i] = find(T[i], i)        push(T[i], i)    }        return result}func find(t int, index int) int {    for i:=top; i>=0; i-- {        if stack[i].temperature > t {            return stack[i].index - index        }    }    return 0}func push(t int, i int) {    for top >=0 && stack[top].temperature <= t {        top--    }    top++    element := ele{i, t}    stack[top] = element}