[Hash] programmers problemset

Author: Seogeurim

Diff for: README.md

@@ -260,10 +260,13 @@
 
 ### Hash
 
-|  #  |  ☆  | Problem                                    | Note |
-| :-: | :-: | :----------------------------------------- | :--- |
-| 01  |     | [Programmers 베스트앨범](./src/Hash/prg42579) |      |
-| 02  |     | [Baekjoon-1764 듣보잡](./src/Hash/P1764)     |      |
+|  #  |  ☆  | Problem                                           | Note |
+| :-: | :-: | :------------------------------------------------ | :--- |
+| 01  |     | [Programmers 베스트앨범](./src/Hash/prg42579)        |      |
+| 02  |     | [Baekjoon-1764 듣보잡](./src/Hash/P1764)            |      |
+| 03  |     | [Programmers 완주하지 못한 선수](./src/Hash/prg42576) |      |
+| 04  |     | [Programmers 전화번호 목록](./src/Hash/prg42577)     |      |
+| 05  |     | [Programmers 위장](./src/Hash/prg42578)            |      |
 
 ## Graph
 

Diff for: src/Hash/prg42576/README.md

@@ -0,0 +1,3 @@
+## [programmers - 해시] 완주하지 못한 선수
+
+![image](https://user-images.githubusercontent.com/22045163/115870709-95bba480-a47a-11eb-82e3-1a5b1e9ca39b.png)

Diff for: src/Hash/prg42576/Solution.java

@@ -0,0 +1,25 @@
+package Hash.prg42576;
+
+import java.util.*;
+
+class Solution {
+
+    HashMap<String, Integer> map = new HashMap<>();
+
+    public String solution(String[] participant, String[] completion) {
+
+        for (String p : participant) {
+            map.merge(p, 1, Integer::sum);
+        }
+
+        for (String c : completion) {
+            if (map.get(c) == 1) map.remove(c);
+            else map.put(c, map.get(c)-1);
+        }
+
+        String ans = "";
+        for (String s : map.keySet()) ans = s;
+
+        return ans;
+    }
+}

Diff for: src/Hash/prg42577/README.md

@@ -0,0 +1,3 @@
+## [programmers - 해시] 전화번호 목록
+
+![image](https://user-images.githubusercontent.com/22045163/115870938-e4693e80-a47a-11eb-9bcf-c13922426edd.png)

Diff for: src/Hash/prg42577/Solution.java

@@ -0,0 +1,21 @@
+package Hash.prg42577;
+
+import java.util.*;
+
+class Solution {
+
+    HashSet<String> set = new HashSet<>();
+
+    public boolean solution(String[] phone_book) {
+
+        Collections.addAll(set, phone_book);
+
+        for (String p : phone_book) {
+            for (int i = 1; i < p.length(); i++) {
+                if (set.contains(p.substring(0, i))) return false;
+            }
+        }
+
+        return true;
+    }
+}

Diff for: src/Hash/prg42578/README.md

@@ -0,0 +1,3 @@
+## [programmers - 해시] 위장
+
+![image](https://user-images.githubusercontent.com/22045163/115871061-0793ee00-a47b-11eb-9a9b-f3343273b160.png)

Diff for: src/Hash/prg42578/Solution.java

@@ -0,0 +1,22 @@
+package Hash.prg42578;
+
+import java.util.*;
+
+class Solution {
+
+    HashMap<String, Integer> map = new HashMap<>();
+    int ans = 1;
+
+    public int solution(String[][] clothes) {
+
+        for (String[] c : clothes) {
+            map.merge(c[1], 1, Integer::sum);
+        }
+
+        for (int val : map.values()) {
+            ans *= val+1;
+        }
+
+        return ans-1;
+    }
+}