matrix

Author: tanfanhua

src/com/blankj/medium/_0059/Solution.java

@@ -0,0 +1,56 @@
+package com.blankj.medium._059;
+
+
+public class Solution {
+
+    public static void main(String[] args) {
+        Solution s = new Solution();
+        s.displayMatrix(s.generateSpiralMatrix(3));
+        s.displayMatrix(s.generateSpiralMatrix(4));
+    }
+
+    private void displayMatrix(int[][] matrix) {
+        for (int[] column : matrix) {
+            for (int e : column) {
+                System.out.print(e);
+                System.out.print(" ");
+            }
+            System.out.println("\n");
+        }
+    }
+
+    public int[][] generateSpiralMatrix(int n) {
+        int[][] res = new int[n][n];
+        int count = 1;
+        int top = 0;
+        int right = 0;
+        int left = n;
+        int bottom = n;
+        int total = n * n;
+        while (count <= total) {
+            int i = top;
+            int j = right;
+            for (; j < left; j++) {
+                res[i][j] = count++;
+            }
+            j = left - 1;
+            for (i = top + 1; i < bottom; i++) {
+                res[i][j] = count++;
+            }
+            i = bottom - 1;
+            for (j = left - 2; j >= right; j--) {
+                res[i][j] = count++;
+            }
+            j = right;
+            for (i = bottom - 2; i > top; i--) {
+                res[i][j] = count++;
+            }
+            top = top + 1;
+            left = left - 1;
+            bottom = bottom - 1;
+            right = right + 1;
+        }
+
+        return res;
+    }
+}