【Monotonic stack】 LCR 038. Daily temperature

LCR 038. Daily temperature

Problem-solving ideas

• monotonic stack
• Find each element with an index greater than its first element
• If not write 0 directly

class Solution {
    
    
    public int[] dailyTemperatures(int[] temperatures) {
    
    
        // 单调栈

        int n = temperatures.length;
        int[] res = new int[n];
        Stack<Integer> s = new Stack<>();// 存放元素的索引


        for(int i = n - 1; i >= 0; i--){
    
    
            while(!s.isEmpty() && temperatures[s.peek()] <= temperatures[i]){
    
    
                s.pop();
            }

            // 针对当前元素
            res[i] = s.isEmpty() ? 0 : (s.peek() - i);
            s.push(i);
        }

        return res;
    }
}