leetcode面試題之go實現順時針打印矩陣

順時針打印矩陣

輸入一個矩陣，按照從外向裏以順時針的順序依次打印出每一個數字。
示例 1：

輸入：matrix = [[1,2,3],[4,5,6],[7,8,9]]
輸出：[1,2,3,6,9,8,7,4,5]
示例 2：

輸入：matrix = [[1,2,3,4],[5,6,7,8],[9,10,11,12]]
輸出：[1,2,3,4,8,12,11,10,9,5,6,7]

Go語言實現

package main
func printMatrix(matrix [][]int) []int {
	result := []int{}
	row := len(matrix)
	if row == 0 {
		return result
	}
	column := len(matrix[0])
	if column == 0 {
		return result
	}
	//定義下標變量
	top := 0
	bottom := row - 1
	left := 0
	right := column - 1
	for left <= right && top <= bottom {
		//從左往右，行數爲top，列數從left開始，+1直到right
		for i := left; i <= right; i++ {
			result = append(result, matrix[top][i])
		}
		//從上往下，行數從top+1開始，+1直到bottom，列數爲right
		for i := top + 1; i <= bottom; i++ {
			result = append(result, matrix[i][right])
		}
		//row不重複，從右往左，行數爲bottom，列數從right-1開始，-1直到left
		if top != bottom {
			for i := right - 1; i >= left; i-- {
				result = append(result, matrix[bottom][i])
			}
		}
		//column不重複，從下往上，行數從bottom-1開始，-1直到top-1，所以沒有等號
		if left != right {
			for i := bottom - 1; i > top; i-- {
				result = append(result, matrix[i][left])
			}
		}
		//一圈結束
		left++
		right--
		top++
		bottom--
	}
	return result
}
func main(){
a:=[][]int{
	{1, 2, 3},
	{4, 5, 6},
	{7, 8, 9},
}
fmt.Println(printMatrix(a))
}

運行結果