package cap3

func Work4(n int) [][]int {
    matrix := make([][]int, n)
    // 逐行长度递减的上三角矩阵
    for i := range matrix {
        matrix[i] = make([]int, n-i)
    }

    // 沿右上方向斜向上填充
    num := 1
    for i := 0; i < n; i++ {
        for j := 0; j <= i; j++ {
            matrix[i-j][j] = num
            num++
        }
    }

    return matrix
}