feat: implement matrix operations logic (rotate and shiftRow)

- Implemented rotate: rotates the outer layer of the matrix clockwise
- Implemented shiftRow: shifts all rows downward by one
- Separated col1, col2, and rows for better performance and clearer logic
- Iterated over operations array to apply each command
- Assembled final matrix using getAnswer() for output

Author: skyleedevzero86

src/com/algorithm2025/backjoon2/Sample20250519_Q1186.java

@@ -0,0 +1,77 @@
+package com.algorithm2025.backjoon2;
+
+import java.util.ArrayDeque;
+import java.util.LinkedList;
+
+public class Sample20250519_Q1186 { //코딩테스트 연습 2022 KAKAO TECH INTERNSHIP 행렬과 연산
+
+    int r, c;
+    ArrayDeque<Integer> col1, col2;
+    LinkedList<ArrayDeque<Integer>> rows;
+
+    private void init(int[][] rc) {
+        r = rc.length;
+        c = rc[0].length;
+
+        col1 = new ArrayDeque<>();
+        col2 = new ArrayDeque<>();
+        for (int i = 0; i < r; i++) {
+            col1.add(rc[i][0]);
+            col2.add(rc[i][c-1]);
+        }
+
+        rows = new LinkedList<>();
+        for (int i = 0; i < r; i++) {
+            ArrayDeque<Integer> tmp = new ArrayDeque<>();
+            for (int j = 1; j < c-1; j++) {
+                tmp.add(rc[i][j]);
+            }
+            rows.add(tmp);
+        }
+    }
+
+    private int[][] getAnswer() {
+        int[][] ans = new int[r][c];
+        for (int i = 0; i < r; i++) {
+            ans[i][0] = col1.pollFirst();
+            ans[i][c-1] = col2.pollFirst();
+        }
+        int i = 0;
+        for (ArrayDeque<Integer> row : rows) {
+            for (int j = 1; j < c-1; j++) {
+                ans[i][j] = row.pollFirst();
+            }
+            i++;
+        }
+        return ans;
+    }
+
+    private void rotate() {
+        if (c == 2) {
+            col2.addFirst(col1.pollFirst());
+            col1.addLast(col2.pollLast());
+            return;
+        }
+        rows.peekFirst().addFirst(col1.pollFirst());
+        col2.addFirst(rows.peekFirst().pollLast());
+        rows.peekLast().addLast(col2.pollLast());
+        col1.addLast(rows.peekLast().pollFirst());
+    }
+
+    private void shiftRow() {
+        rows.addFirst(rows.pollLast());
+        col1.addFirst(col1.pollLast());
+        col2.addFirst(col2.pollLast());
+    }
+
+    public int[][] Sample20250519_Q1186(int[][] rc, String[] operations) {
+        init(rc);
+        for (String op : operations) {
+            switch (op.charAt(0)) {
+                case 'R' : rotate();    break;
+                case 'S' : shiftRow();  break;
+            }
+        }
+        return getAnswer();
+    }
+}