Mun: 5월 2주차 문제 풀이

05월/2주차/[LCD] Longest Common Prefix/Mun.java

@@ -0,0 +1,24 @@
+
+class Mun {
+    public String longestCommonPrefix(String[] strs) {
+        StringBuilder sb = new StringBuilder("");
+        String basic = strs[0];
+        for(int i=0;i<basic.length();i++) {
+            boolean in = true;
+            for(String str : strs) {
+                if(str.length() <= i || basic.charAt(i) != str.charAt(i)) {
+                    in = false;
+                    break;
+                }
+            }
+
+            if(in) {
+                sb.append(basic.charAt(i));
+            } else {
+                break;
+            }
+        }
+
+        return sb.toString();
+    }
+}

05월/2주차/[LCD] Roman to Integer/Mun.java

@@ -0,0 +1,42 @@
+import java.util.*;
+
+class Mun {
+    HashMap<String, Integer> map = new HashMap<>(){{
+        put("I", 1);
+        put("V", 5);
+        put("X", 10);
+        put("L", 50);
+        put("C", 100);
+        put("D", 500);
+        put("M", 1000);
+        put("IV", 4);
+        put("IX", 9);
+        put("XL", 40);
+        put("XC", 90);
+        put("CD", 400);
+        put("CM", 900);
+    }};
+
+    public int romanToInt(String s) {
+        if(s.length() == 1) {
+            return map.get(s);
+        }
+
+        int sum = 0;
+        for(int i=0;i<s.length();i++) {
+            if(i==s.length()-1) {
+                sum+=map.get(s.substring(i, i+1));
+                break;
+            }
+            String str = s.substring(i, i+2);
+            if(map.containsKey(str)) {
+                sum+=map.get(str);
+                i++;
+            } else {
+                sum+=map.get(str.split("")[0]);
+            }
+        }
+
+        return sum;
+    }
+}