There is a two-dimensional array, how to get 2 or 3 random numbers from a cross (not adjacent to the top, bottom, left, and right)?
Array:
var a = [
[0, 1],
[2, 3],
[4, 5],
[6, 7]
];
I wrote one like this, but it feels very rigid. The numbers obtained are not even and the code is a bit bloated. Does anyone have a better solution?
function select() {
var a = [
[0, 1],
[2, 3],
[4, 5],
[6, 7]
];
var lastSelect = -1;
for (var i = 0; i < a.length; i++) {
var index = getRandomNumber(lastSelect, a[i].length);
console.log(a[i][index]);
lastSelect = index;
}
}
function getRandomNumber(lastSelect, max) {
var random = Math.floor(Math.random() * max);
if (random == lastSelect) return getRandomNumber(lastSelect, max);
else return random;
}
select()
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The condition is that the top, bottom, left and right are not adjacent. Assuming that the starting point coordinate is (0,0), then the following points (-1, 0), (0, -1), (1, 0), (0, 1) are masked. The characteristics of these points are: the absolute value of x plus the absolute value of y equals 1. Random x and y coordinate values within a reasonable range and add the absolute values of each. If it is not equal to 1 and this coordinate has not been taken before, it is legal.
Here is a very simple hack idea that fully meets the needs, that is, deliberately [taking numbers at cross-sections] to achieve the requirement of [not adjacent to the top, bottom, left, and right]. It only requires two lines: