59.Spiral Matrix II
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 ] ]
思路：
题目意思是给一个数n，让生成一个
n*n的螺旋方阵，思路和54题很像，都是记录下需要访问的那一圈的四个顶点，作为遍历的依据。然后从1开始放数字就可以
代码：
go：
代码语言：javascript复制func generateMatrix(n int) [][]int {
var res = make([][]int, n)
for i := range res {
res[i] = make([]int, n)
}
fillNumber(&res, 0, n-1, 0, n -1, 1)
return res
}
func fillNumber(res *[][]int, top, bottom, left, right int, num int) {
if top > bottom || left > right {
return
}
if top == bottom {
for i := left; i <= right; i {
(*res)[top][i] = num
num
}
} else if left == right {
for i := top; i < bottom; i {
(*res)[i][left] = num
num
}
} else {
// 从左到右
for i := left; i <= right - 1; i {
(*res)[top][i] = num
num
}
// 从上到下
for i := top; i <= bottom - 1; i {
(*res)[i][right] = num
num
}
// 从左到右
for i := right; i >= left 1; i-- {
(*res)[bottom][i] = num
num
}
// 从下到上
for i := bottom; i >= top 1; i-- {
(*res)[i][left] = num
num
}
}
fillNumber(res, top 1, bottom-1, left 1, right-1, num)
}
