[BOJ]선분 위의 점/실버3/1시간

Author: developHeo515

junsu/week11/BOJ11663 선분 위의 점/BOJ11663.java

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+//BOJ11663 선분 위의 점, 실버3
+import java.io.*;
+import java.util.*;
+
+public class BOJ11663 {
+	static int N, M;
+	static long[] point;
+	public static void main(String[] args) throws IOException {
+		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());
+		point = new long[N];
+		
+		st = new StringTokenizer(br.readLine());
+		for(int i = 0; i < N; i++) {
+			int n = Integer.parseInt(st.nextToken());
+			point[i] = n;
+		}
+		Arrays.sort(point);
+		
+		long ans = 0;
+		for(int j = 0; j < M; j++) {
+			st = new StringTokenizer(br.readLine());
+			int x = Integer.parseInt(st.nextToken());
+			int y = Integer.parseInt(st.nextToken());
+			
+			ans = BinarySearch(x, y);
+			bw.write(ans +"\n");
+		}
+		bw.flush();
+		bw.close();
+		br.close();
+	}
+	static long BinarySearch(int x, int y) {
+		int start = 0;
+		int end = point.length-1;
+		
+		while(start <= end) {
+			int mid = (start + end) / 2;
+			
+			if(point[mid] < x) {
+				start = mid + 1;
+			}else {
+				end = mid - 1;
+			}
+		}
+		int startIndex = start;
+		
+		start = 0;
+		end = point.length-1;
+		
+		while(start <= end) {
+			int mid = (start + end) / 2;
+			
+			if(y < point[mid]) {
+				end = mid - 1;
+			}else { 
+				start = mid + 1;
+			}
+		}
+		int endIndex = end + 1;
+		
+//		System.out.println(startIndex + " " + endIndex);
+		return endIndex - startIndex;
+	}
+}
+
+
+
+