added shift 2D grid

Author: saihariG

Matrix/Shift2DGrid.java

@@ -0,0 +1,50 @@
+package Matrix;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Shift2DGrid {
+    public List<List<Integer>> shiftGrid(int[][] grid, int k) {
+        int row = grid.length;
+        int col = grid[0].length;
+
+        // Create temporary array of the same size in which we will add element in new position after k shifting.
+        int[][] temp = new int[row][col];
+
+        // Solution Approach:
+        // Assume if we convert given array into 1D Array then shift element to k positions and after shifting all the elements we will again convert 1D Array to our original dimension array.
+
+        // Logic for Finding current elements index in 1D Array after shifting K times :
+        // For current element We will just find that what will be its index in 1D Array
+        // After for New position in 1D Array we will shift it k times means we will add K in current index
+        // And if new position in 1D Array gets increased by its total size, we will modulo it by 1D Array Size
+
+        for(int i = 0; i < row; i++) {
+            for(int j = 0; j < col; j++) {
+
+                // (i * col) + j : will Give Index in 1D Array
+                // (i * col) + j + k : Adding K means we will shift it k times
+                // ((i * col) + j + k ) % (row * col) : modulo it by array size (row * col), if it exceeds the size
+                int indexIn1DArray = ((i * col) + j + k ) % (row * col);
+
+                // Now Based on the 1D Array Index we will find its index in our temporary result array
+                int tempRowIndex = indexIn1DArray / col; // Find the particular row
+                int tempColIndex = indexIn1DArray % col; // Find the particular column
+                temp[tempRowIndex][tempColIndex] = grid[i][j]; // Add Element at that new index in our temporary result array
+            }
+        }
+
+        // Prepare Result in List
+        List<List<Integer>> result = new ArrayList<List<Integer>>();
+
+        for(int i = 0; i < row; i++) {
+            List<Integer> list = new ArrayList<Integer>();
+            for(int j = 0; j < col; j++) {
+                list.add(temp[i][j]);
+            }
+            result.add(list);
+        }
+
+        return result;
+    }
+}