Java Algorithm

Author: par3k

BOJ_JAVA/out/production/BOJ_JAVA/BOJ/BOJ_1946$Node.class

@@ -0,0 +1,48 @@
+package BOJ;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.*;
+
+public class BOJ_1946 {
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        int T = Integer.parseInt(br.readLine());
+
+        for (int tc = 1; tc <= T; tc++) {
+            int N = Integer.parseInt(br.readLine());
+            ArrayList<Node> arr = new ArrayList<>();
+            for (int i = 0;  i< N; i++) {
+                StringTokenizer st= new StringTokenizer(br.readLine());
+                int s1 = Integer.parseInt(st.nextToken());
+                int s2 = Integer.parseInt(st.nextToken());
+                arr.add(new Node(s1, s2));
+            }
+
+            Collections.sort(arr, (s1, s2) -> s1.s1 - s2.s1);
+
+            int tmp = arr.get(0).s2;
+            int ans = 0;
+
+            for (int i = 0; i < arr.size(); i++) {
+                if (arr.get(i).s2 > tmp) {
+                    ans++;
+                } else {
+                    tmp = arr.get(i).s2;
+                }
+
+            }
+            System.out.println(N - ans);
+        }
+        br.close();
+    }
+
+    static class Node{
+        int s1, s2;
+        public Node(int s1, int s2) {
+            this.s1 = s1;
+            this.s2 = s2;
+        }
+    }
+}