739.Daily Temperatures

tags: Medium,Array,Stack

739. Daily Temperatures

題目描述

Given an array of integers temperatures represents the daily temperatures, return an array answer such that answer[i] is the number of days you have to wait after the i^th day to get a warmer temperature. If there is no future day for which this is possible, keep answer[i] == 0 instead.

範例

Example 1:

Input: temperatures = [73,74,75,71,69,72,76,73]
Output: [1,1,4,2,1,1,0,0]

Example 2:

Input: temperatures = [30,40,50,60]
Output: [1,1,1,0]

Example 3:

Input: temperatures = [30,60,90]
Output: [1,1,0]

Constraints:

• 1 <= temperatures.length <= 10⁵
• 30 <= temperatures[i] <= 100

解答

Javascript

function dailyTemperatures(temperatures) {
  const result = [];
  for (let i = 0; i < temperatures.length; i++) {
    result[i] = 0;
  }
    
  const stack = [];
  for (let i = 0; i < temperatures.length; i++) {
    while (stack.length && temperatures[i] > temperatures[stack[stack.length - 1]]) {
      const current = stack.pop();
      result[current] = i - current;
    }
    stack.push(i); // 只存index就可以了
  }

  return result;
}

Marsgoat Dec 18, 2022

C#

public class Solution {
    public int[] DailyTemperatures(int[] temperatures) {
        int[] output = new int[temperatures.Length];

        for (int i = temperatures.Length - 1; i >= 0; i--) {
            int j = i + 1;
            while (j < temperatures.Length) {
                if (temperatures[j] > temperatures[i]) {
                    output[i] = j - i;
                    break;
                }

                j += Math.Max(1, output[j]);
            }
        }

        return output;
    }
}

Reference

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