LeetCode-in-All

739. Daily Temperatures

Medium

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 ith day to get a warmer temperature. If there is no future day for which this is possible, keep answer[i] == 0 instead.

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:

Solution

class Solution {
  List<int> dailyTemperatures(List<int> temperatures) {
    List<int> sol = List.filled(temperatures.length, 0);
    sol[temperatures.length - 1] = 0;

    for (int i = sol.length - 2; i >= 0; i--) {
      int j = i + 1;
      while (j < sol.length) { // Use '<' instead of '<='
        if (temperatures[i] < temperatures[j]) {
          sol[i] = j - i;
          break;
        } else {
          if (sol[j] == 0) {
            break;
          }
          j = j + sol[j];
        }
      }
    }
    return sol;
  }
}