[20251110] BOJ / G4 / 점프 / 설진영

Author: Seol-JY

Seol-JY/202511/10 BOJ G4 점프.md

@@ -0,0 +1,63 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        
+        int N = Integer.parseInt(st.nextToken());
+        int M = Integer.parseInt(st.nextToken());
+        
+        boolean[] canStep = new boolean[N + 1];
+        Arrays.fill(canStep, true);
+        
+        for (int i = 0; i < M; i++) {
+            int small = Integer.parseInt(br.readLine());
+            canStep[small] = false;
+        }
+        
+        int maxSpeed = 200;
+        int[][] dist = new int[N + 1][maxSpeed + 1];
+        for (int i = 0; i <= N; i++) {
+            Arrays.fill(dist[i], Integer.MAX_VALUE);
+        }
+        
+        PriorityQueue<int[]> pq = new PriorityQueue<>((a, b) -> a[2] - b[2]);
+        pq.offer(new int[]{1, 0, 0});
+        dist[1][0] = 0;
+        
+        while (!pq.isEmpty()) {
+            int[] cur = pq.poll();
+            int pos = cur[0];
+            int speed = cur[1];
+            int jumps = cur[2];
+            
+            if (pos == N) {
+                System.out.println(jumps);
+                return;
+            }
+            
+            if (dist[pos][speed] < jumps) {
+                continue;
+            }
+            
+            for (int nextSpeed = Math.max(1, speed - 1); nextSpeed <= speed + 1; nextSpeed++) {
+                int nextPos = pos + nextSpeed;
+                
+                if (nextPos > N || nextPos < 1 || !canStep[nextPos] || nextSpeed > maxSpeed) {
+                    continue;
+                }
+                
+                if (dist[nextPos][nextSpeed] > jumps + 1) {
+                    dist[nextPos][nextSpeed] = jumps + 1;
+                    pq.offer(new int[]{nextPos, nextSpeed, jumps + 1});
+                }
+            }
+        }
+        
+        System.out.println(-1);
+    }
+}
+```