题目：

题解：

class Solution {
public:vector<vector<int>> generateMatrix(int n) {int num = 1;vector<vector<int>> matrix(n, vector<int>(n));int left = 0, right = n - 1, top = 0, bottom = n - 1;while (left <= right && top <= bottom) {for (int column = left; column <= right; column++) {matrix[top][column] = num;num++;}for (int row = top + 1; row <= bottom; row++) {matrix[row][right] = num;num++;}if (left < right && top < bottom) {for (int column = right - 1; column > left; column--) {matrix[bottom][column] = num;num++;}for (int row = bottom; row > top; row--) {matrix[row][left] = num;num++;}}left++;right--;top++;bottom--;}return matrix;}
};