[Stack] programmers 주식가격

Author: Seogeurim

README.md

@@ -203,6 +203,7 @@
 | 05  | ⭐️ | [Baekjoon-2867 수열의 값](./src/Stack/P2867)    |      |
 | 06  |     | [SWEA-1218 괄호 짝짓기](./src/Stack/swea1218)   |      |
 | 07  |     | [SWEA-1223 계산기2](./src/Stack/swea1223)      |      |
+| 08  |     | [Programmers 주식가격](./src/Stack/prg42584)    |      |
 
 ### Queue
 

src/Stack/prg42584/README.md

@@ -0,0 +1,3 @@
+## [programmers - 스택/큐] 주식가격
+
+![image](https://user-images.githubusercontent.com/22045163/115883783-2600e600-a489-11eb-86ed-42fb02091879.png)

src/Stack/prg42584/Solution.java

@@ -0,0 +1,32 @@
+package Stack.prg42584;
+
+import java.util.*;
+
+class Solution {
+    public int[] solution(int[] prices) {
+
+        int N = prices.length;
+        int[] res = new int[N];
+        Stack<Price> s = new Stack<>();
+
+        for (int i = 0; i < N; i++) {
+            int cur = i == N-1 ? 0 : prices[i];
+            while (!s.isEmpty() && s.peek().price > cur) {
+                Price p = s.pop();
+                res[p.time] = i - p.time;
+            }
+            s.push(new Price(cur, i));
+        }
+
+        return res;
+    }
+}
+
+class Price {
+    int price, time;
+
+    public Price(int price, int time) {
+        this.price = price;
+        this.time = time;
+    }
+}