Given a positive integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.
Example:
Input: 3 Output: [ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ]
1 class Solution { 2 public: 3 vector<vector<int>> generateMatrix(int n) { 4 vector<vector<int> > res( n, vector<int>(n) ); 5 int n1 =1; 6 int c1=0,c2=n-1; 7 int r1=0,r2=n-1; 8 while(c1<=c2&&r1<=r2){ 9 for(int c =c1;c<=c2;c++,n1++) res[r1][c] =n1; 10 for(int r =r1+1;r<=r2;r++,n1++) res[r][c2] =n1; 11 if(c1<=c2&&r1<=r2){ 12 for(int c =c2-1;c>=c1;c--,n1++) res[r2][c] =n1; 13 for(int r =r2-1;r>=r1+1;r--,n1++) res[r][c1] =n1; 14 } 15 c1++;c2--;r1++;r2--; 16 } 17 return res; 18 } 19 20 };
原文：https://www.cnblogs.com/zle1992/p/10223754.html