// 从外到里打印矩阵matrix
var displayMatrix = (matrix) => {
// 设置上下左右边界
let top = 0
let bottom = matrix.length - 1
let left = 0
let right = matrix[0].length - 1
let res = []
while (true) {
// 从左到右这个方向
for (let i = left; i <= right; i++) {
(matrix[top][i])
}
top++;
if (top > bottom) {
break
}
// 从上到下
for (let i = top; i <= bottom; i++) {
(matrix[i][right])
}
right--
if (right < left) {
break
}
// 从右到左
for (let i = right; i >= left; i--) {
(matrix[bottom][i])
}
bottom--
if (bottom < top) {
break
}
// 从下到上
for (let i = bottom; i >= top; i--) {
(matrix[i][left])
}
left++
if (left > right) {
break
}
}
// res数组保存了输出的顺序
}