[04주차 박민수] 구간 합 구하기 5

01주차/박민수/1931.java

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+import java.io.*;
+import java.util.*;
+
+/***
+ * 백준 1931번
+ * 회의실 배정
+ * 2023-10-09
+ */
+
+public class Main {
+
+    static class Meeting implements Comparable<Meeting> {
+        private int start;
+        private int end;
+
+        public Meeting(int start, int end) {
+            this.start = start;
+            this.end = end;
+        }
+
+        @Override
+        public int compareTo(Meeting o) {
+            // 회의 끝 (오름차순 정렬)
+            if (this.end > o.end) {
+                return 1;
+            } else if(this.end < o.end) {
+                return - 1;
+            } else
+                // 회의 끝 시간 같을 시, 회의 시작 (오름차순 정렬)
+                return this.start - o.start;
+        }
+    }
+
+    public static void main(String[] args) throws IOException {
+
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+        int n = Integer.parseInt(br.readLine());
+
+        List<Meeting> meetings = new ArrayList<>();
+
+        StringTokenizer st = null;
+        for (int i = 0; i < n; i++) {
+            st = new StringTokenizer(br.readLine());
+            int s = Integer.parseInt(st.nextToken());
+            int e = Integer.parseInt(st.nextToken());
+            meetings.add(new Meeting(s, e));
+        }
+
+        // 회의 끝을 오름차순으로 정렬
+        Collections.sort(meetings);
+
+
+        int end = 0;
+        int answer = 0;
+
+        // 정렬된 회의에서 가장 빨리 끝나는 회의와 겹치지 않는 것을 카운팅하고, 가장 빨리 끝나는 회의 갱신
+        for (Meeting meeting : meetings) {
+            if (meeting.start >= end) {
+                end = meeting.end;
+                answer++;
+            }
+        }
+
+        System.out.println(answer);
+    }
+}

02주차/박민수/Main.java

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+package BFS.BOJ13549;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Arrays;
+import java.util.LinkedList;
+import java.util.Queue;
+import java.util.StringTokenizer;
+
+public class Main {
+
+    public static class Distance {
+        int x;
+        int time;
+
+        public Distance(int x, int time) {
+            this.x = x;
+            this.time = time;
+        }
+    }
+
+    static int N; // 수빈이의 위치
+    static int K; // 동생의 위치
+    static final int DISTANCE_MAX = 100000;
+    static int[] counter = new int[100001]; // INDEX : 현재위치, VALUE : 최소이동횟수
+
+    static Queue<Integer> q = new LinkedList<>();
+
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        K = Integer.parseInt(st.nextToken());
+        Arrays.fill(counter, Integer.MAX_VALUE);
+
+        // 처음 위치 큐에 삽입
+        q.add(N);
+        counter[N] = 0;
+        while(!q.isEmpty()) {
+            int now = q.poll();
+
+            if (now == K) {
+                System.out.println(counter[K]);
+                break;
+            }
+
+            // 걷는 경우, 순간이동 하는 경우 계산
+            for (int i = 0; i < 3; i++) {
+
+                switch (i) {
+                    case 0:
+                        if (now - 1 >= 0 && counter[now - 1] > counter[now] + 1) {
+                            q.add(now - 1);
+                            counter[now - 1] = counter[now] + 1;
+                        }
+                        break;
+                    case 1:
+                        if (now + 1 <= DISTANCE_MAX && counter[now + 1] > counter[now] + 1) {
+                            q.add(now + 1);
+                            counter[now + 1] = counter[now] + 1;
+                        }
+                        break;
+                    case 2:
+                        if (now * 2 <= DISTANCE_MAX && counter[now * 2] > counter[now]) {
+                            q.add(now * 2);
+                            counter[now * 2] = counter[now];
+                        }
+                        break;
+                }
+            }
+        }
+    }
+}

04주차/박민수/Main.java

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+package ClassFour.BOJ11660;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+/***
+ * 백준 11660번
+ * 구간 합 구하기 5
+ * 2023-11-17
+ *
+ */
+
+public class Main {
+    static int N; // 1 <= N <= 1024
+    static int M; // 1 <= M <= 100,000
+    static int x1, y1, x2, y2; // x1 <= x2, y1 <= y2
+    static int[][] numbers;
+    static int[][] dp;
+    public static void main(String[] args) throws IOException {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        N = Integer.parseInt(st.nextToken());
+        M = Integer.parseInt(st.nextToken());
+
+        numbers = new int[N + 1][N + 1];
+        dp = new int[N + 1][N + 1];
+
+        for (int i = 1; i <= N; i++) {
+            st = new StringTokenizer(br.readLine());
+            for (int j = 1; j <= N;j ++) {
+                numbers[i][j] = Integer.parseInt(st.nextToken());
+                // 행 누적합 저장
+                if (j == 1) {
+                    dp[i][j] = numbers[i][j];
+                } else {
+                    dp[i][j] = dp[i][j - 1] + numbers[i][j];
+                }
+            }
+        }
+
+        StringBuilder sb = new StringBuilder();
+
+        for (int i = 0; i < M; i++) {
+            st = new StringTokenizer(br.readLine());
+            x1 = Integer.parseInt(st.nextToken());
+            y1 = Integer.parseInt(st.nextToken());
+            x2 = Integer.parseInt(st.nextToken());
+            y2 = Integer.parseInt(st.nextToken());
+
+            int total = 0;
+
+            for (int a = x1; a <= x2; a++) {
+                total += (dp[a][y2] - dp[a][y1 - 1]);
+            }
+            sb.append(total).append("\n");
+        }
+
+        System.out.println(sb);
+    }
+}