[feat] 24주차

src/main/java/org/example/_24week/NQueens.java

@@ -0,0 +1,70 @@
+package org.example._24week;
+
+public class NQueens {
+
+    private static int[][] map;
+    private static int n;
+    private static int answer = 0;
+
+    private static final int ROW = 0;
+    private static final int COL = 1;
+
+    public static void main(String[] args) {
+        int _n = 4;
+        final int solution = solution(4);
+        System.out.println(solution);
+    }
+
+    private static int solution(final int _n) {
+        n = _n;
+        map = new int[n][n];
+        final int[][] selectedPositions = new int[n][2];
+        dfs(0, 0, 0, selectedPositions);
+
+        return answer;
+    }
+
+    private static void dfs(final int row, final int col, int depth, int[][] selectedPositions) {
+        if (depth == n) {
+            answer++;
+            return;
+        }
+
+        for (int i = row; i < n; i++) {
+            for (int j = i == row ? col : 0; j < n; j++) {
+                if (isInValid(depth,selectedPositions, i, j)) {
+                    continue;
+                }
+
+                selectedPositions[depth] = new int[]{i, j};
+                dfs(i, j + 1, depth + 1, selectedPositions);
+                selectedPositions[depth] = null;
+            }
+        }
+    }
+
+    private static boolean isInValid(final int depth, final int[][] selectedPositions, final int newPositionRow, final int newPositionCol) {
+        for (int i = 0; i < depth; i++) {
+            final int[] selectedPosition = selectedPositions[i];
+
+            // 가로
+            if (selectedPosition[COL] == newPositionCol) {
+                return true;
+            }
+            // 세로
+            if (selectedPosition[ROW] == newPositionRow) {
+                return true;
+            }
+            // Slash /
+            if (selectedPosition[ROW] + selectedPosition[COL] == newPositionRow + newPositionCol) {
+                return true;
+            }
+            // backSlash \
+            if (selectedPosition[ROW] - selectedPosition[COL] == newPositionRow - newPositionCol) {
+                return true;
+            }
+        }
+
+        return false;
+    }
+}

src/main/java/org/example/_24week/NQueens2.java

@@ -0,0 +1,71 @@
+package org.example._24week;
+
+public class NQueens2 {
+
+    private static int n;
+    private static int answer = 0;
+    private static int wrong = 0;
+
+    private static boolean[] visitedCol;
+    private static boolean[] visitedBackSlash = new boolean[23];
+    private static boolean[] visitedSlash = new boolean[23];
+
+    public static void main(String[] args) {
+        final long startTime = System.nanoTime();
+        final int solution = solution(12);
+        final long endTime = System.nanoTime();
+
+        System.out.println(endTime - startTime);
+
+        System.out.println(solution);
+        System.out.println(wrong);
+    }
+
+    private static int solution(final int _n) {
+        n = _n;
+        visitedCol = new boolean[n];
+        final int[][] selectedPositions = new int[n][2];
+        dfs(0, selectedPositions);
+
+        return answer;
+    }
+
+    private static void dfs(final int row, int[][] selectedPositions) {
+        if (row == n) {
+            answer++;
+            return;
+        }
+
+        for (int newCol = 0; newCol < n; newCol++) {
+            final int slash = row + newCol;
+            final int backSlash = row - newCol >= 0 ? row - newCol : newCol - row + 11;
+
+            if (isInValid(newCol, slash, backSlash)) {
+                continue;
+            }
+
+            visitedCol[newCol] = true;
+            visitedSlash[slash] = true;
+            visitedBackSlash[backSlash] = true;
+
+            selectedPositions[row] = new int[]{row, newCol};
+            dfs(row + 1, selectedPositions);
+
+            visitedCol[newCol] = false;
+            visitedSlash[slash] = false;
+            visitedBackSlash[backSlash] = false;
+        }
+    }
+
+    private static boolean isInValid(final int newPositionCol, final int slash, final int backSlash) {
+        if (
+            visitedCol[newPositionCol] ||
+                visitedSlash[slash] ||
+                visitedBackSlash[backSlash]
+        ) {
+            return true;
+        }
+
+        return false;
+    }
+}

src/main/java/org/example/_24week/TrainingCenter.java

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+package org.example._24week;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Arrays;
+import java.util.StringTokenizer;
+import java.util.stream.Collectors;
+
+public class TrainingCenter {
+
+    private static final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+
+    public static void main(String[] args) throws IOException {
+        StringTokenizer st = new StringTokenizer(br.readLine());
+        final int N = Integer.parseInt(st.nextToken());
+        final int M = Integer.parseInt(st.nextToken());
+
+        final int[] heights = Arrays.stream(br.readLine().split(" ")).mapToInt(Integer::parseInt).toArray();
+        final int[] querys = new int[N];
+        for (int i = 0; i < M; i++) {
+            st = new StringTokenizer(br.readLine());
+            final int a = Integer.parseInt(st.nextToken()) - 1;
+            final int b = Integer.parseInt(st.nextToken());
+            final int amount = Integer.parseInt(st.nextToken());
+
+            querys[a] += amount;
+            if (b < N) {
+                querys[b] -= amount;
+            }
+        }
+
+        for (int i = 1; i < N; i++) {
+            querys[i] += querys[i - 1];
+        }
+
+        final StringBuilder sb = new StringBuilder();
+        for (int i = 0; i < N; i++) {
+            heights[i] += querys[i];
+            sb.append(heights[i]).append(" ");
+        }
+
+        System.out.println(sb);
+    }
+}