我的任务是创建一个包含所有排列/给定数字数组的 4 位数字的数组:[1,2,3,4,5,6,7,8,9]。数字不能重复,因为每个值必须是唯一的。以下是我的解决方案,但我正在努力将递归应用于该过程。我希望它具有适应性,因此如果条件发生变化,即该函数必须生成 5 位数字甚至 6 位数字的所有组合,因为需要更改的代码很少,并且添加递归可以轻松实现这一点。正如您在下面看到的,代码确实有效,但如果条件发生变化,则需要更多嵌套的 for 循环。 我正在寻找递归解决方案。这似乎不是一个好的解决方案,但任何建议将不胜感激。我在网上看到很多关于创建 4P4 或 5P5 但不是 9P5 类型样式的解决方案。我尝试应用堆的算法但没有成功。
function arrayCreate((availableNumbers, userNumberArray)) {
var possibleValues = []; //empty array to house all the possible combination of values that the user could enter i.e. 1234 to 9876
var numberOfPermutations = (factorial(availableNumbers.length) / factorial(availableNumbers.length - userNumberArray.length));
var adding = true;
var firstDigit, secondDigit, thirdDigit, forthDigit =0;
var possibleDigitValue = "";
while (adding === true) {
for (var i = 0; i < availableNumbers.length; i++) {
firstDigit = availableNumbers[i];
availableNumbers.splice(i, 1);
for (var j = 0; j < availableNumbers.length; j++) {
secondDigit = availableNumbers[j];
availableNumbers.splice(j, 1);
for (var k = 0; k < availableNumbers.length; k++) {
thirdDigit = availableNumbers[k]
availableNumbers.splice(k, 1);
for (var l = 0; l < availableNumbers.length; l++) {
forthDigit = availableNumbers[l];
possibleDigitValue = (firstDigit + secondDigit + thirdDigit + forthDigit);
possibleValues.push(possibleDigitValue);
}
availableNumbers.splice(k, 0, thirdDigit);
}
availableNumbers.splice(j, 0, secondDigit);
}
availableNumbers.splice(i, 0, firstDigit);
if (possibleValues.length >= numberOfPermutations) {
adding = false;
}
}
console.log(possibleValues);
return possibleValues;
}
}
arrayCreate([1,2,3,4,5,6,7,8,9],[0,0,0,0]);
var userNumberArray = ['0', '0', '0', '0']; //empty array of 0's as this value is not allowed, this array will store the computers auto-generated number
var availableNumbers = ['1', '2', '3', '4', '5', '6', '7', '8', '9'] //array of available numbers to be picked and added to the computerNumber array
//this function is used later to calculate the possible permutations of combinations of user guess
function factorial(x) {
if (x === 0) { return 1; }
else{
return x * factorial(x-1);
}
}
function arrayCreate(availableNumbers, userNumberArray) {
var possibleValues = []; //empty array to house all the possible combination of values that the user could enter i.e. 1234 to 9876
var numberOfPermutations = (factorial(availableNumbers.length) / factorial(availableNumbers.length - userNumberArray.length));
var adding = true;
var firstDigit, secondDigit, thirdDigit, forthDigit =0;
var possibleDigitValue = "";
while (adding === true) {
for (var i = 0; i < availableNumbers.length; i++) {
firstDigit = availableNumbers[i];
availableNumbers.splice(i, 1);
for (var j = 0; j < availableNumbers.length; j++) {
secondDigit = availableNumbers[j];
availableNumbers.splice(j, 1);
for (var k = 0; k < availableNumbers.length; k++) {
thirdDigit = availableNumbers[k]
availableNumbers.splice(k, 1);
for (var l = 0; l < availableNumbers.length; l++) {
forthDigit = availableNumbers[l];
possibleDigitValue = (firstDigit + secondDigit + thirdDigit + forthDigit);
possibleValues.push(possibleDigitValue);
}
availableNumbers.splice(k, 0, thirdDigit);
}
availableNumbers.splice(j, 0, secondDigit);
}
availableNumbers.splice(i, 0, firstDigit);
if (possibleValues.length >= numberOfPermutations) {
adding = false;
}
}
return possibleValues;
}
}
console.log(arrayCreate(availableNumbers, userNumberArray));
最佳答案
您可以采用递归方法,迭代项目并检查之前是否已选择该项目。如果没有,则取出该项目并检查零件数组的长度。
如果具有所需的长度,请将零件数组放入结果中。
如果没有,则迭代给定数组并移交部分数组。
function arrayCreate(array, size) {
var result = [];
array.forEach(function iter(parts) {
return function (v) {
var temp = parts.concat(v);
if (parts.includes(v)) {
return;
}
if (temp.length === size) {
result.push(temp);
return;
}
array.forEach(iter(temp));
}
}([]));
return result;
}
console.log(arrayCreate([1, 2, 3, 4, 5, 6, 7, 8, 9], 4).map(a => a.join('')));
console.log(arrayCreate([1, 2, 3, 4, 5, 6, 7, 8, 9], 5).map(a => a.join('')));
console.log(arrayCreate([1, 2, 3, 4, 5, 6, 7, 8, 9], 6).map(a => a.join('')));
.as-console-wrapper { max-height: 100% !important; top: 0; }
具有分离的函数iter
。
function arrayCreate(array, size) {
function iter(parts) {
return function (v) {
var temp = parts.concat(v);
if (parts.includes(v)) {
return;
}
if (temp.length === size) {
result.push(temp);
return;
}
array.forEach(iter(temp));
}
}
var result = [];
array.forEach(iter([]));
return result;
}
console.log(arrayCreate([1, 2, 3, 4, 5, 6, 7, 8, 9], 4).map(a => a.join('')));
console.log(arrayCreate([1, 2, 3, 4, 5, 6, 7, 8, 9], 5).map(a => a.join('')));
console.log(arrayCreate([1, 2, 3, 4, 5, 6, 7, 8, 9], 6).map(a => a.join('')));
.as-console-wrapper { max-height: 100% !important; top: 0; }
关于javascript - 创建一个由所有唯一的 4 位数字组成的数组,这些数字可以由 JavaScript 中的数字 1-9 组成,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/49652068/