javascript - 将列矩阵中的所有零移动到末尾

Question

我有以下矩阵

var matrix = [
    [2,    0,    0,  2],
    [4,    0,    0,  2],
    [2,    64,   32, 4],
    [1024, 1024, 64, 0]
];

而且我想将第一行和第二行的第二列和第三列的零移到末尾，但我不知道该怎么做。这是我的尝试:

for(var i = 0; i < matrix.length; i++) {
    for(var j = 0; j < matrix.length ;j++) {
        //push zeroes to the end
        if(matrix[j][i] === 0){
            for(var k = j+1; k<2;k++){
                matrix[j][i] = matrix[k][i]
            }
            matrix[3][i] = 0
        }
    }
}

这是它返回的结果与我的预期:

Returns:  [[2, 0,  0,  2], [4, 0,    0,  2], [2, 64, 32, 4], [1024, 0, 0, 0]]
Expected: [[2, 64, 32, 2], [4, 1024, 64, 2], [2, 0,  0,  4], [1024, 0, 0, 0]]

如果有任何帮助，我将不胜感激

Answer 1

要在每一列上移动零，您可以转置矩阵，移动每一行并将其转回:

let zip = a => a[0].map((_, i) => a.map(b => b[i]))

let shiftZeros = a => a.filter(x => x).concat(a.filter(x => !x))

//

let matrix = [
    [2,    0,    0,  2],
    [4,    0,    0,  2],
    [2,    64,   32, 4],
    [1024, 1024, 64, 0]
];

result = zip(zip(matrix).map(shiftZeros))

console.log(result.map(x => x.join()))