Daily Coding Problem: Problem #315

秒速五厘米 2023-06-01 12:53 12阅读 0赞

/**
     * This problem was asked by Google.
    
    In linear algebra,
    a Toeplitz matrix is one in which the elements on any given diagonal from top left to bottom right are identical.
    
    Here is an example:
    1 2 3 4 8
    5 1 2 3 4
    4 5 1 2 3
    7 4 5 1 2
    Write a program to determine whether a given input is a Toeplitz matrix.
     * */
    class Problem_315 {
        fun isToeplitz(): Boolean {
            //5行4列的matrix
            var mat = arrayOf(
                intArrayOf(6, 7, 8, 9),
                intArrayOf(4, 6, 7, 8),
                intArrayOf(1, 4, 6, 7),
                intArrayOf(0, 1, 4, 6),
                intArrayOf(2, 0, 1, 4)
            )
    
            /*mat = arrayOf(
                intArrayOf(6, 3, 8),
                intArrayOf(4, 9, 7),
                intArrayOf(1, 4, 6)
            )*/
    
            val row = mat.size
            val col = mat[0].size
    
            //check begin from row
            for (i in 0..(row - 1)) {
                if (!checkDiagonal(mat, i, 0)) {
                    return false
                }
            }
            //check begin from col
            for (i in 0..(col - 1)) {
                if (!checkDiagonal(mat, 0, i)) {
                    return false
                }
            }
    
            return true
        }
    
        private fun checkDiagonal(matrix: Array<IntArray>, i_: Int, j_: Int): Boolean {
            val row = matrix.size
            val col = matrix[0].size
            var i = i_
            var j = j_
            val res = matrix[i][j]
            while (++i < row && ++j < col) {
                if (matrix[i][j] != res) {
                    return false
                }
            }
            return true
        }
    }

转载于:https://www.cnblogs.com/johnnyzhao/p/11108508.html