Merge branch 'week9'

Author: spring0913

week9/Programmers_43162(네트워크).java

@@ -0,0 +1,26 @@
+class Solution {
+
+    private boolean[] visited;
+
+    public int solution(int n, int[][] computers) {
+        int count = 0;
+        visited = new boolean[n];
+        for(int i=0; i<n; i++) {
+            if(!visited[i]) {
+                count++;
+                dfs(computers, i);
+            }
+        }
+        return count;
+    }
+
+    public void dfs(int[][] computers, int v) {
+        int len = computers.length;
+        for(int i=0; i<len; i++) {
+            if(!visited[i] && computers[v][i] == 1) {
+                visited[i] = true;
+                dfs(computers, i);
+            }
+        }
+    }
+}

week9/Programmers_43165(타겟 넘버).java

@@ -0,0 +1,21 @@
+class Solution {
+
+    private int count = 0;
+
+    public int solution(int[] numbers, int target) {
+        dfs(numbers, target, 0, 0);
+        return count;
+    }
+
+    public void dfs(int[] numbers, int target, int index, int n) {
+        if(index == numbers.length) {
+            if(n == target) {
+                count++;
+            }
+            return;
+        }
+
+        dfs(numbers, target, index+1, n + numbers[index]);
+        dfs(numbers, target, index+1, n - numbers[index]);
+    }
+}

week9/Programmers_87694(아이템 줍기).java

@@ -0,0 +1,72 @@
+import java.util.*;
+
+class Solution {
+
+    private int[][] board;
+
+    public int solution(int[][] rectangle, int characterX, int characterY, int itemX, int itemY) {
+        int len = rectangle.length;
+        board = new int[101][101];
+
+        // 좌표를 두 배로 확대해서 도형의 테두리 공간을 만든다
+        for(int i=0; i<len; i++) {
+            int x1 = rectangle[i][0] * 2;
+            int y1 = rectangle[i][1] * 2;
+            int x2 = rectangle[i][2] * 2;
+            int y2 = rectangle[i][3] * 2;
+
+            // 좌표*2 도형 내부를 1로 채우기
+            for(int j=y1; j<=y2; j++) {
+                for(int k=x1; k<=x2; k++) {
+                    board[j][k] = 1;
+                }
+            }
+        }
+
+        for(int i=0; i<len; i++) {
+            int x1 = rectangle[i][0] * 2;
+            int y1 = rectangle[i][1] * 2;
+            int x2 = rectangle[i][2] * 2;
+            int y2 = rectangle[i][3] * 2;
+
+            // 도형의 테두리만 남기고 나머지를 0으로 채우기
+            for(int j=y1+1; j<=y2-1; j++) {
+                for(int k=x1+1; k<=x2-1; k++) {
+                    board[j][k] = 0;
+                }
+            }
+        }
+        int result = bfs(rectangle, characterX*2, characterY*2, itemX*2, itemY*2);
+        return result/2;
+    }
+
+    public int bfs(int[][] rectangle, int characterW, int characterH, int itemW, int itemH) {
+        int[] dh = {0, 1, 0, -1};
+        int[] dw = {-1, 0, 1, 0};
+        int[][] visited = new int[101][101];
+
+        Queue<int[]> q = new LinkedList<>();
+        q.offer(new int[]{characterH, characterW});
+        while(!q.isEmpty()) {
+            int h = q.peek()[0];
+            int w = q.peek()[1];
+            q.poll();
+
+            if(h == itemH && w == itemW) {
+                return visited[h][w];
+            }
+
+            for(int i=0; i<4; i++) {
+                int nextH = h + dh[i];
+                int nextW = w + dw[i];
+                if(nextH >= 0 && nextH <= 100 && nextW >= 0 && nextW <= 100) {
+                    if(visited[nextH][nextW] == 0 && board[nextH][nextW] == 1) {
+                        visited[nextH][nextW] = visited[h][w]+1;
+                        q.offer(new int[]{nextH, nextW});
+                    }
+                }
+            }
+        }
+        return 0;
+    }
+}

week9/Programmers_92343(양과 늑대).java

@@ -0,0 +1,39 @@
+class Solution {
+
+    private boolean[] visited;
+    private int answer = 0;
+    private int[] info;
+    private int[][] edges;
+
+    public int solution(int[] _info, int[][] _edges) {
+        answer = 0;
+        info = _info;
+        edges = _edges;
+        visited = new boolean[info.length+1];
+        visited[0] = true;
+        dfs(1, 0);
+        return answer;
+    }
+
+    public void dfs(int sheep, int wolf) {
+        if(wolf < sheep) {
+            answer = Math.max(answer, sheep);
+        }else {
+            return;
+        }
+
+        for(int i=0; i<edges.length; i++) {
+            int parent = edges[i][0];
+            int child = edges[i][1];
+            if(visited[parent] && !visited[child]) {
+                visited[child] = true;
+                if(info[child] == 0) {
+                    dfs(sheep+1, wolf);
+                }else {
+                    dfs(sheep, wolf+1);
+                }
+                visited[child] = false;
+            }
+        }
+    }
+}