20240728 조이썬(이영수) - 2주차

.gitignore

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+.idea

boj/youngsu5582/week1/1260.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.ArrayDeque;
+import java.util.Deque;
+import java.util.StringTokenizer;
+
+public class Main {
+    private static final StringBuilder sb = new StringBuilder();
+
+    public static void main(final String[] args) throws IOException {
+        final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(reader.readLine(), " ");
+
+        int n = Integer.parseInt(st.nextToken());
+        int m = Integer.parseInt(st.nextToken());
+        final int v = Integer.parseInt(st.nextToken());
+
+
+        final int[][] ary = new int[n + 1][n + 1];
+        final boolean[] visited = new boolean[n + 1];
+        final boolean[] visited2 = visited.clone();
+        for (int i = 0; i < m; i++) {
+            st = new StringTokenizer(reader.readLine(), " ");
+            final int x = Integer.parseInt(st.nextToken());
+            final int y = Integer.parseInt(st.nextToken());
+            ary[x][y] = 1;
+            ary[y][x] = 1;
+        }
+        dfs(visited, ary, v);
+        sb.append("\n");
+        bfs(visited2, ary, v);
+        System.out.println(sb);
+
+    }
+
+    public static void dfs(boolean[] visited, int[][] ary, int pos) {
+        visited[pos] = true;
+        sb.append(pos)
+                .append(" ");
+        for (int i = 1; i < ary[pos].length; i++) {
+            if (!visited[i] && ary[pos][i] == 1) {
+                dfs(visited, ary, i);
+            }
+        }
+    }
+
+    public static void bfs(boolean[] visited, int[][] ary, int pos) {
+        Deque<Integer> temp = new ArrayDeque<>();
+        temp.add(pos);
+        while (!temp.isEmpty()) {
+            pos = temp.pollFirst();
+            if (visited[pos]) {
+                continue;
+            }
+            visited[pos] = true;
+            sb.append(pos)
+                    .append(" ");
+            for (int i = 1; i < ary[pos].length; i++) {
+                if (!visited[i] && ary[pos][i] == 1) {
+                    temp.add(i);
+                }
+            }
+        }
+    }
+
+}

boj/youngsu5582/week1/2606.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.StringTokenizer;
+
+public class Main {
+    private static boolean[] visited;
+    private static int[][] ary;
+    private static int n;
+    private static int count;
+
+    public static void main(final String[] args) throws IOException {
+        final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
+
+        n = Integer.valueOf(reader.readLine());
+        int m = Integer.parseInt(reader.readLine());
+
+        ary = new int[n + 1][n + 1];
+
+        for (int i = 0; i < m; i++) {
+            StringTokenizer st = new StringTokenizer(reader.readLine(), " ");
+            int x = Integer.parseInt(st.nextToken());
+            int y = Integer.parseInt(st.nextToken());
+            ary[x][y] = 1;
+            ary[y][x] = 1;
+        }
+
+        visited = new boolean[n + 1];
+        dfs(1);
+        System.out.println(count-1);
+    }
+
+    public static void dfs(int pos) {
+        visited[pos] = true;
+        count++;
+        for (int i = 1; i <= n; i++) {
+            if(!visited[i] && ary[pos][i]==1) {
+                dfs(i);
+            }
+        }
+    }
+
+}

boj/youngsu5582/week1/2839.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+
+public class Main {
+    private static final StringBuilder sb = new StringBuilder();
+
+    public static void main(final String[] args) throws IOException {
+        final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
+        final int n = Integer.parseInt(reader.readLine());
+
+        int result = Integer.MAX_VALUE;
+
+        for(int i = 0; i*5 <=n; i++) {
+            for(int j = 0; i*5 + j*3 <=n; j++) {
+                if(i*5 + j*3 == n){
+                    result = Math.min(result,i+j);
+                }
+            }
+        }
+
+        if(result==Integer.MAX_VALUE){
+            sb.append(-1);
+        }else{
+            sb.append(result);
+        }
+
+        System.out.println(sb);
+    }
+}

boj/youngsu5582/week2/1461.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Collections;
+import java.util.Optional;
+import java.util.PriorityQueue;
+import java.util.StringTokenizer;
+
+public class Main {
+    private static PriorityQueue<Integer> plus = new PriorityQueue<>(Collections.reverseOrder());
+    private static PriorityQueue<Integer> minus = new PriorityQueue<>(Collections.reverseOrder());
+    private static int n;
+    private static int m;
+    private static int sum = 0;
+
+    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());
+
+        st = new StringTokenizer(br.readLine(), " ");
+        while (st.hasMoreTokens()) {
+            int number = Integer.parseInt(st.nextToken());
+            if (number > 0) {
+                plus.add(number);
+            } else {
+                minus.add(number * -1);
+            }
+        }
+
+        int max = findMax();
+        add(plus);
+        add(minus);
+
+        System.out.println(sum - max);
+    }
+
+    public static int findMax() {
+        int plus = Optional.ofNullable(Main.plus.peek())
+                .orElse(-1);
+        int minus = Optional.ofNullable(Main.minus.peek())
+                .orElse(-1);
+        return plus > minus ? plus : minus;
+    }
+
+    public static void add(PriorityQueue<Integer> pq) {
+        int count = 0;
+        int temp = -1;
+        while (!pq.isEmpty()) {
+            temp = Math.max(pq.poll(), temp);
+            count++;
+            if (count == m) {
+                count = 0;
+                sum += temp * 2;
+                temp = -1;
+            }
+        }
+        if (temp == -1) {
+            return;
+        }
+        sum += temp * 2;
+    }
+}

boj/youngsu5582/week2/1890.java

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+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.math.BigInteger;
+import java.util.Arrays;
+import java.util.StringTokenizer;
+
+public class Main {
+    private static int[][] list;
+    private static BigInteger[][] dp;
+    private static int n;
+
+    public static void main(final String[] args) throws IOException {
+        final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
+
+        n = Integer.valueOf(reader.readLine());
+
+        list = new int[n][n];
+        dp = new BigInteger[n][n];
+
+        for (int i = 0; i < n; i++) {
+            StringTokenizer st = new StringTokenizer(reader.readLine(), " ");
+            int index = 0;
+            while (st.hasMoreTokens()) {
+                list[i][index++] = Integer.valueOf(st.nextToken());
+            }
+        }
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < n; j++) {
+                dp[i][j] = BigInteger.ZERO;
+            }
+        }
+
+        dp[0][0] = BigInteger.ONE;
+
+        for (int i = 0; i < n; i++) {
+            for (int j = 0; j < n; j++) {
+                execute(i, j);
+            }
+        }
+        System.out.println(dp[n - 1][n - 1]);
+    }
+
+    public static void execute(int x, int y) {
+        int count = list[x][y];
+        if (list[x][y] == 0) {
+            return;
+        }
+        int nextX = x + count;
+        int nextY = y + count;
+        if (nextY < n) {
+            dp[x][nextY] = dp[x][y].add(dp[x][nextY]);
+        }
+        if (nextX < n) {
+            dp[nextX][y] = dp[x][y].add(dp[nextX][y]);
+        }
+    }
+}