[英]Generating all possible combinations of strings
I am trying to generate all possible combinations of a string. 我正在尝试生成字符串的所有可能组合。
eg for the list below: a1q5z!H9, b1q5z!H9, c1q5z!H9, d1q5z!H9, a2q5z!H9 ... etc 例如,对于下面的列表:a1q5z!H9,b1q5z!H9,c1q5z!H9,d1q5z!H9,a2q5z!H9 ......等
Rather than make lots of nested loops, I thought I would try something clever with MODULO ... but hit a wall. 而不是制作大量嵌套循环,我想我会尝试用MODULO聪明的东西......但是碰壁了。
This is the Javascript I have come up with - any pointers to how I might go on? 这是我想出的Javascript - 我可能会怎么做的任何指示?
var c = [
['a', 'b', 'c', 'd'],
['1', '2', '3', '4'],
['q', 'w', 'e', 'r'],
['5', '6', '7', '8'],
['z', 'x', 'c', 'v'],
['!', '"', '£', '$'],
['H', 'J', 'K', 'L'],
['9', '8', '7', '6'],
];
var o = document.getElementById('output');
var pw = "";
var chars = c.length;
for( var i = 0; i <20; i++)
{
pw = ""
for(var j = 0; j < chars; j++ )
{
pw += c[j][i%4];
}
op(pw);
}
function op(s)
{
o.innerHTML = o.innerHTML + "<br>" + s;
}
This just outputs the first 20 in the list, but repeats ... I nearly have it but not quite. 这只是输出列表中的前20个,但重复...我几乎拥有它但不完全。 Any help or pointers appreciated. 任何帮助或指针赞赏。
Quite easy to write a recursive function demo . 编写递归函数演示非常容易。
function permutate(abc, memo) {
var options;
memo = memo || abc.shift().slice(0);
if(abc.length) {
options = abc.shift();
return permutate(abc, memo.reduce(function(all, item){
return all.concat(options.map(function(option){
return item + option;
}))
}, []));
}
return memo;
};
console.log(permutate(c).length); //65536 items
Or more imperative approach 或者更迫切的方法
function permutate2(abc) {
var options, i, len, tmp, j, optionsLen,
memo = abc.pop().slice(0); //copy first the last array
while(options = abc.pop()) { //replace recursion
tmp = [];
optionsLen = options.length;
for(i = 0, len = memo.length; i < len; i++) { //for every element in memo
for(j = 0; j < optionsLen; j++) { //do cartesian product with options
tmp.push(options[j] + memo[i]);
}
}
memo = tmp;
}
return memo;
}
This is how I did it: 我就是这样做的:
string password;
bool done = false;
while (!done) {
password = string.Empty;
for(int a = 0; a < blah[0].Length; a++) {
for(int b = 0; b < blah[1].Length; b++) {
for (int c = 0; c < blah[2].Length; c++) {
for (int d= 0; d < blah[3].Length; d++) {
for (int e = 0; e < blah[4].Length; e++) {
for (int f = 0; f < blah[5].Length; f++) {
for (int g = 0; g < blah[6].Length; g++) {
for (int h = 0; h < blah[7].Length; h++) {
password = string.Format(
"{0}{1}{2}{3}{4}{5}{6}{7}",
blah[0][a],
blah[1][b],
blah[2][c],
blah[3][d],
blah[4][e],
blah[5][f],
blah[6][g],
blah[7][h]);
Console.Out.WriteLine(password);
}
}
}
}
}
}
}
}
}
Where blah is the character matrix. blah是字符矩阵。
Ugly, granted, but the shorter answer by Yury hurts my head. 丑陋,被授予,但Yury的简短回答伤害了我的头脑。
function combinations(str) {
debugger;
var arr = [];
for (var i = 0; i < str.length; i++)
{
// create an empty string
var comb = "";
// loop for substring
for (var j = i; j < str.length; j++)
{
comb+=str[j];
arr.push(comb);
}
}
return arr;
}
console.log(combinations('output'));
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