Given an integer n, generate a square matrix filled with elements from 1 to n2 in spiral order.
For example,
Given n = 3,
[ [ 1, 2, 3 ], [ 8, 9, 4 ], [ 7, 6, 5 ] ]
给定整数n, 将1,2,3...nxn个数按螺旋旋转的方式填入nxn的矩阵
同Spiral Matrix, 从外圈到内圈依次填写
class Solution {
public:
void generate(vector<vector<int> >&matrix, int i, int j, int len, int num){
//i, j 当前圈左上角的坐标
//len 当前圈的边长
//num 将填入当前圈的第一个数值
if(len<1)return;
if(len==1){
matrix[i][j]=num;
return;
}
//填写上面的边
int x=i, y=j;
while(y<j+len-1){
matrix[x][y++]=num++;
}
//填写后面的边
while(x<i+len-1){
matrix[x++][y]=num++;
}
//填写下面的边
while(y>j){
matrix[x][y--]=num++;
}
//填写左面的边
while(x>i){
matrix[x--][y]=num++;
}
//填写内圈
generate(matrix, i+1, j+1, len-2, num);
}
vector<vector<int> > generateMatrix(int n) {
vector<vector<int> >result(n, vector<int>(n, 0));
generate(result, 0, 0, n, 1);
return result;
}
};LeetCode: Spiral Matrix II [058],布布扣,bubuko.com
LeetCode: Spiral Matrix II [058]
原文：http://blog.csdn.net/harryhuang1990/article/details/26814291