[20251114] PGM / LV3 / 여행경로 / 강신지

ksinji/202511/14 PGM 여행경로.md

@@ -0,0 +1,53 @@
+```
+import java.util.*;
+
+class Solution {
+    private String[][] tickets;
+    private boolean[] used;
+    private List<String> answer;
+    private int n;
+
+    public String[] solution(String[][] tickets) {
+        this.tickets = tickets;
+        this.n = tickets.length;
+        this.used = new boolean[n];
+
+        Arrays.sort(this.tickets, (a, b) -> {
+            if (!a[0].equals(b[0])) {
+                return a[0].compareTo(b[0]);
+            }
+            return a[1].compareTo(b[1]);
+        });
+
+        List<String> path = new ArrayList<>();
+        path.add("ICN");
+
+        dfs("ICN", 0, path);
+
+        return answer.toArray(new String[0]);
+    }
+
+    private boolean dfs(String current, int count, List<String> path) {
+        if (count == n) {
+            answer = new ArrayList<>(path);
+            return true;
+        }
+
+        for (int i = 0; i < n; i++) {
+            if (!used[i] && tickets[i][0].equals(current)) {
+                used[i] = true;
+                path.add(tickets[i][1]);
+
+                if (dfs(tickets[i][1], count + 1, path)) {
+                    return true;
+                }
+
+                path.remove(path.size() - 1);
+                used[i] = false;
+            }
+        }
+
+        return false;
+    }
+}
+```