[2020kakao(intern)-p3] 보석 쇼핑

Author: Seogeurim

README.md

@@ -515,5 +515,6 @@
 
 |  #  |  ☆  | Problem                                       | Note |
 | :-: | :-: | :-------------------------------------------- | :--- |
-| 01  |     | [키패드 누르기](./src/_2020_카카오_인턴십/P1) |      |
-| 02  |     | [수식 최대화](./src/_2020_카카오_인턴십/P2) |      |
+| 01  |     | [키패드 누르기](./src/_2020_카카오_인턴십/P1)       |      |
+| 02  |     | [수식 최대화](./src/_2020_카카오_인턴십/P2)         |  구현  |
+| 03  |     | [보석 쇼핑](./src/_2020_카카오_인턴십/P3)          |  2-pointer |

src/_2020_카카오_인턴십/P3/Main.java

@@ -0,0 +1,48 @@
+package _2020_카카오_인턴십.P3;
+
+import java.util.Arrays;
+import java.util.HashMap;
+import java.util.HashSet;
+
+public class Main {
+
+    public static void main(String[] args) {
+        Solution sol = new Solution();
+        System.out.println(Arrays.toString(sol.solution(new String[]{"DIA", "RUBY", "RUBY", "DIA", "DIA", "EMERALD", "SAPPHIRE", "DIA"})));
+        System.out.println(Arrays.toString(sol.solution(new String[]{"AA", "AB", "AC", "AA", "AC"})));
+        System.out.println(Arrays.toString(sol.solution(new String[]{"XYZ", "XYZ", "XYZ"})));
+        System.out.println(Arrays.toString(sol.solution(new String[]{"DIA", "EM", "EM", "RUB", "DIA"}))); // 3, 5
+        System.out.println(Arrays.toString(sol.solution(new String[]{"ZZZ", "YYY", "NNNN", "YYY", "BBB"})));
+    }
+}
+
+class Solution {
+
+    public int[] solution(String[] gems) {
+
+        HashSet<String> set = new HashSet<>(Arrays.asList(gems));
+        int n = gems.length, size = set.size();
+        int ans_low = 0, ans_high = n-1;
+
+        int low = 0, high = 0;
+        HashMap<String, Integer> map = new HashMap<>();
+        map.put(gems[low], 1);
+        while (low < n && high < n) {
+            if (map.size() < size) {
+                high ++;
+                if (high < n) map.merge(gems[high], 1, Integer::sum);
+            } else {
+                if (map.size() == size &&
+                    ((ans_high - ans_low) > (high - low) || low < ans_low)) {
+                    ans_low = low;
+                    ans_high = high;
+                }
+                if (map.get(gems[low]) != null) map.put(gems[low], map.get(gems[low])-1);
+                if (map.get(gems[low]) == 0) map.remove(gems[low]);
+                low ++;
+            }
+        }
+
+        return new int[]{ans_low+1, ans_high+1};
+    }
+}

src/_2020_카카오_인턴십/P3/README.md

@@ -0,0 +1,3 @@
+## [2020 카카오 인턴십] 보석 쇼핑
+
+![image](https://user-images.githubusercontent.com/22045163/116556898-eb8bc300-a938-11eb-80f8-648894529e70.png)