[20250319] BOJ / 골드1 / 최솟값과 최댓값 / 이강현

lkhyun/202503/19 BOJ 골드1 최솟값.md

@@ -0,0 +1,62 @@
+```java
+import java.util.*;
+import java.io.*;
+
+class Node{
+    long min;
+    long max;
+    Node(long min,long max){
+        this.min = min;
+        this.max = max;
+    }
+}
+public class Main {
+    static int N;
+    static int M;
+    static long[] arr;
+    static Node[] tree;
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+        arr = new long[N*4];
+        tree = new Node[N*4];
+
+        for(int i=1;i<=N;i++){
+            arr[i] = Long.parseLong(br.readLine());
+        }
+        init(1,1,N);
+        for(int i=0;i<M;i++){
+            st = new StringTokenizer(br.readLine());
+            int left = Integer.parseInt(st.nextToken());
+            int right = Integer.parseInt(st.nextToken());
+            Node n = query(1,1,N,left,right);
+            bw.write(n.min+" "+n.max+"\n");
+        }
+        bw.close();
+    }
+    public static void init(int cur, int start, int end){
+        if(start == end){
+            tree[cur] = new Node(arr[start],arr[start]);
+            return;
+        }
+
+        init(cur*2,start,(start+end)/2);
+        init(cur*2 + 1, (start+end)/2 + 1, end);
+        tree[cur] = new Node(Math.min(tree[cur*2].min,tree[cur*2 + 1].min),
+                             Math.max(tree[cur*2].max,tree[cur*2 + 1].max));
+    }
+    public static Node query(int cur, int start, int end, int left, int right){
+        if(left>end || right<start) return null;
+        if(left<=start && right>=end) return tree[cur];
+
+        Node l = query(cur*2,start,(start+end)/2,left,right);
+        Node r = query(cur*2+1,(start+end)/2 + 1, end,left,right);
+        if(l==null)return r;
+        else if(r==null) return l;
+        else return new Node(Math.min(l.min,r.min),Math.max(l.max,r.max));
+    }
+}
+```