题目描述

给定一个整数n，将数字1到n^2n
2
按螺旋的顺序填入n×n的矩阵
例如：
给出的n=3，
你应该返回如下矩阵：
[
[ 1, 2, 3 ],
[ 8, 9, 4 ],
[ 7, 6, 5 ]
]

class Solution {   public:    /**     *      * @param n int整型      * @return int整型vector
   
    <>>     */    vector
    
     
       > generateMatrix(int n) {           // write code here                vector
      
       
        > matrix(n, vector
        
         (n)); int left = 0; int right = n-1; int up = 0; int down = n-1; int index = 1; while(left <= right && up <= down){ for(int i = left; i <= right && up <= down; i++){ matrix[up][i] = index; index++; } for(int i = up+1; i <= down && left<= right; i++){ matrix[i][right] = index++; } for(int i = right-1; i >= left && up <= down; i--){ matrix[down][i] = index++; } for(int i = down-1; i >= up+1 && left <= right; i--){ matrix[i][left] = index++; } left++; right--; up++; down--; } return matrix; }};