Daily Temperatures

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:

bucket

class Solution {
    public int[] dailyTemperatures(int[] T) {
        int[] buckets = new int[71];
        int[] result = new int[T.length];
        for (int i = T.length - 1; i >= 0; i --) {
            int curTemp = T[i];
            int minIndexHigher = Integer.MAX_VALUE;
            for (int temp = curTemp + 1; temp <= 100; temp ++) {
                if (buckets[temp - 30] != 0) {
                    minIndexHigher = Math.min(minIndexHigher, buckets[temp - 30]);
                }
            }
            buckets[curTemp - 30] = i;
            result[i] = minIndexHigher == Integer.MAX_VALUE ? 0 : minIndexHigher - i;
        }
        return result;
    }
}

class Solution {
    public int[] dailyTemperatures(int[] T) {
        int[] result = new int[T.length];
        Deque<Integer> stack = new ArrayDeque();
        for (int i = 0; i < T.length; i ++) {
            int curTemp = T[i];
            while (!stack.isEmpty() && T[stack.peek()] < curTemp) {
                int colderTempIndex = stack.pop();
                result[colderTempIndex] = i - colderTempIndex;
            }
            stack.push(i);
        }
        return result;
    }
}