2월 1주차

java/src/feb/week1/boj/easy2048_박재환.java

@@ -0,0 +1,194 @@
+package feb.week1.boj;
+
+import java.util.*;
+import java.io.*;
+
+public class easy2048_박재환 {
+    static BufferedReader br;
+    public static void main(String[] args) throws IOException {
+        br = new BufferedReader(new InputStreamReader(System.in));
+        init();
+        br.close();
+    }
+    static StringTokenizer st;
+    static int n;
+    static void init() throws IOException {
+        n = Integer.parseInt(br.readLine().trim());
+        Block[][] map = new Block[n][n];
+        for(int x=0; x<n; x++) {
+            st = new StringTokenizer(br.readLine().trim());
+            for(int y=0; y<n; y++) {
+                int num = Integer.parseInt(st.nextToken());
+                if(num == 0) map[x][y] = null;
+                else map[x][y] = new Block(num);
+            }
+        }
+        int result = solution(map);
+        System.out.println(result);
+    }
+    static class Block {
+        int num;
+        boolean increase;
+
+        Block(int num) {
+            this.num = num;
+        }
+    }
+    /**
+     * 이동방향은 총 4가지 방향
+     * 상, 하, 좌, 우
+     * 5번 이동했을 때 최대
+     * 4 ** 5
+     */
+    static int topValue;
+    static int solution(Block[][] map) {
+        topValue = 2;
+        moveBlock(0, map);
+        return topValue;
+    }
+    static int getTopValue(Block[][] map) {
+        int top = 0;
+        for(int x=0; x<n; x++) {
+            for(int y=0; y<n; y++) {
+                if(map[x][y] == null) continue;
+                top = Math.max(map[x][y].num, top);
+            }
+        }
+        return top;
+    }
+    static void moveBlock(int seq, Block[][] map) {
+        if(seq == 5) {
+            int top = getTopValue(map);
+            topValue = Math.max(top, topValue);
+            return;
+        }
+        /**
+         * 계속해서 map을 Copy 해서 새로운 map으로 생성
+         */
+        for(int dir=0; dir<4; dir++) {
+            Block[][] copy = copyMap(map);
+            switch(dir) {
+                case 0:
+                    left(copy);
+                    break;
+                case 1:
+                    right(copy);
+                    break;
+                case 2:
+                    top(copy);
+                    break;
+                case 3:
+                    bottom(copy);
+                    break;
+            }
+            moveBlock(seq+1, copy);
+        }
+
+    }
+    static void left(Block[][] map) {
+        Deque<Block> q = new ArrayDeque<>();
+        for(int x=0; x<n; x++) {
+            q.clear();
+            for(int y=0; y<n; y++) {
+                if(map[x][y] == null) continue;
+                // 빈칸이 아닐 때
+                if(!q.isEmpty() && !q.getLast().increase && q.getLast().num == map[x][y].num) {
+                    q.getLast().increase = true;
+                } else {
+                    q.offer(map[x][y]);
+                }
+            }
+            for(int y=0; y<n; y++) {
+                if(!q.isEmpty()) {
+                    Block block = q.poll();
+                    if(block.increase) block.num *= 2;
+                    map[x][y] = block;
+                } else {
+                    map[x][y] = null;
+                }
+            }
+        }
+    }
+    static void right(Block[][] map) {
+        Deque<Block> q = new ArrayDeque<>();
+        for(int x=0; x<n; x++) {
+            q.clear();
+            for(int y=n-1; y>-1; y--) {
+                if(map[x][y] == null) continue;
+                // 빈칸이 아닐 때
+                if(!q.isEmpty() && !q.getLast().increase && q.getLast().num == map[x][y].num) {
+                    q.getLast().increase = true;
+                } else {
+                    q.offer(map[x][y]);
+                }
+            }
+            for(int y=n-1; y>-1; y--) {
+                if(!q.isEmpty()) {
+                    Block block = q.poll();
+                    if(block.increase) block.num *= 2;
+                    map[x][y] = block;
+                } else {
+                    map[x][y] = null;
+                }
+            }
+        }
+    }
+    static void top(Block[][] map) {
+        Deque<Block> q = new ArrayDeque<>();
+        for(int y=0; y<n; y++) {
+            q.clear();
+            for(int x=0; x<n; x++) {
+                if(map[x][y] == null) continue;
+                // 빈칸이 아닐 때
+                if(!q.isEmpty() && !q.getLast().increase && q.getLast().num == map[x][y].num) {
+                    q.getLast().increase = true;
+                } else {
+                    q.offer(map[x][y]);
+                }
+            }
+            for(int x=0; x<n; x++) {
+                if(!q.isEmpty()) {
+                    Block block = q.poll();
+                    if(block.increase) block.num *= 2;
+                    map[x][y] = block;
+                } else {
+                    map[x][y] = null;
+                }
+            }
+        }
+    }
+    static void bottom(Block[][] map) {
+        Deque<Block> q = new ArrayDeque<>();
+        for(int y=0; y<n; y++) {
+            q.clear();
+            for(int x=n-1; x>-1; x--) {
+                if(map[x][y] == null) continue;
+                // 빈칸이 아닐 때
+                if(!q.isEmpty() && !q.getLast().increase && q.getLast().num == map[x][y].num) {
+                    q.getLast().increase = true;
+                } else {
+                    q.offer(map[x][y]);
+                }
+            }
+            for(int x=n-1; x>-1; x--) {
+                if(!q.isEmpty()) {
+                    Block block = q.poll();
+                    if(block.increase) block.num *= 2;
+                    map[x][y] = block;
+                } else {
+                    map[x][y] = null;
+                }
+            }
+        }
+    }
+    static Block[][] copyMap(Block[][] map) {
+        Block[][] copy = new Block[n][n];
+        for(int x=0; x<n; x++) {
+            for(int y=0; y<n; y++) {
+                if(map[x][y] == null) copy[x][y] = null;
+                else copy[x][y] = new Block(map[x][y].num);
+            }
+        }
+        return copy;
+    }
+}

java/src/feb/week1/boj/궁금한민호_박재환.java

@@ -0,0 +1,55 @@
+package feb.week1.boj;
+
+import java.util.*;
+import java.io.*;
+
+public class 궁금한민호_박재환 {
+    static BufferedReader br;
+    public static void main(String[] args) throws IOException {
+        br = new BufferedReader(new InputStreamReader(System.in));
+        init();
+        br.close();
+    }
+    static StringTokenizer st;
+    static int n;
+    static int[][] map;
+    static void init() throws IOException {
+        n = Integer.parseInt(br.readLine().trim());
+        map = new int[n][n];
+        /**
+         * 주어지는 경로는 이미 최소거리
+         */
+        for(int from=0; from<n; from++) {
+            st = new StringTokenizer(br.readLine().trim());
+            for(int to=0; to<n; to++) map[from][to] = Integer.parseInt(st.nextToken());
+        }
+        System.out.println(getMinCostAndMinRoad());
+    }
+    static int getMinCostAndMinRoad() {
+        boolean[][] unUsed = new boolean[n][n];
+        /**
+         * 플로이드 워셜을 이용해서 해당 거리가 최소 거리가 맞는지 검증
+         */
+        for(int mid=0; mid<n; mid++) {
+            for(int from=0; from<n; from++) {
+                for(int to=0; to<n; to++) {
+                    if(mid == from || mid == to || from == to) continue;            // 실제 다른 도시와 연결된 간선만 비교대상으로 판단
+                    if(map[from][to] > map[from][mid] + map[mid][to]) return -1;    // 최소 경로가 아니였을 때
+                    else if(map[from][to] == map[from][mid] + map[mid][to]) {       // 동일한 비용의 경로가 존재한다면 -> 도로의 개수가 최소가 되어야하므로, 경유 도로 제거
+                        unUsed[from][to] = true;
+                    }
+                }
+            }
+        }
+        int sum = 0;
+        for(int from=0; from<n; from++) {
+            for(int to=0; to<n; to++) {
+                if(unUsed[from][to]) continue;
+                sum += map[from][to];
+                unUsed[from][to] = true;
+                unUsed[to][from] = true;
+            }
+        }
+        return sum;
+    }
+}