[20250902] BOJ / G5 / 동전 2 / 이강현

lkhyun/202509/02 BOJ G5 동전 2.md

@@ -0,0 +1,38 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+    static StringTokenizer st;
+    static int N,K;
+    static Set<Integer> coins;
+    static int[] dp; //dp[i]: i원을 만드는데 필요한 동전의 최소 개수
+    public static void main(String[] args) throws IOException {
+        st = new StringTokenizer(br.readLine());
+        N = Integer.parseInt(st.nextToken());
+        K = Integer.parseInt(st.nextToken());
+        coins = new HashSet<>();
+        dp = new int[K+1];
+        for (int i = 0; i < N; i++) {
+            coins.add(Integer.parseInt(br.readLine()));
+        }
+
+        Arrays.fill(dp,Integer.MAX_VALUE);
+        dp[0] = 0;
+
+        for (int i : coins) {
+            for (int j = i; j <= K; j++) {
+                if(dp[j-i] != Integer.MAX_VALUE){
+                    dp[j] = Math.min(dp[j],dp[j-i]+1);
+                }
+            }
+        }
+        int ans = dp[K] == Integer.MAX_VALUE ? -1 : dp[K];
+
+        bw.write(ans + "");
+        bw.close();
+    }
+}
+```