[20250314] BOJ / P5 / Random Generator / 권혁준

khj20006/202503/14 BOJ P5 Random Generator.md

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+```java
+
+import java.util.*;
+import java.io.*;
+
+class SegTree{
+	int[] tree;
+	SegTree(int size){
+		tree = new int[size*4+1];
+	}
+
+	void upt(int s, int e, int i, int v, int n) {
+		if(s == e) {
+			tree[n] = v;
+			return;
+		}
+		int m=(s+e)>>1;
+		if(i <= m) upt(s, m, i, v, n*2);
+		else upt(m+1, e, i, v, n*2+1);
+		tree[n] = tree[n*2] + tree[n*2+1];
+	}
+
+	int find(int s, int e, int v, int n) {
+		if(s == e) return s;
+		int m=(s+e)>>1;
+		if(v <= tree[n*2]) return find(s, m, v, n*2);
+		return find(m+1, e, v-tree[n*2], n*2+1);
+	}
+}
+
+class Main {
+
+	// IO field
+	static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+	static BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
+	static StringTokenizer st = new StringTokenizer("");
+
+	static void nextLine() throws Exception {st = new StringTokenizer(br.readLine());}
+	static int nextInt() throws Exception {
+		if(!st.hasMoreTokens()) nextLine();
+		return Integer.parseInt(st.nextToken());
+	}
+	static long nextLong() throws Exception {
+		if(!st.hasMoreTokens()) nextLine();
+		return Long.parseLong(st.nextToken());
+	}
+	static void bwEnd() throws Exception {bw.flush();bw.close();}
+
+	// Additional field
+
+	static int N;
+	static SegTree seg;
+
+	public static void main(String[] args) throws Exception {
+
+		ready();
+		solve();
+
+		bwEnd();
+
+	}
+
+	static void ready() throws Exception{
+
+		N = nextInt();
+		seg = new SegTree(N);
+		for(int i=1;i<=N;i++) seg.upt(1, N, i, nextInt(), 1);
+
+	}
+
+	static void solve() throws Exception{
+
+		for(int i=1;i<=N;i++) {
+			int p = nextInt();
+			int x = seg.find(1, N, p, 1);
+			bw.write(x + " ");
+			seg.upt(1, N, x, 0, 1);
+		}
+
+	}
+
+}
+
+```