计算一组数字的可能排列 [英] Calculate possible permutations of an array of numbers
问题描述
计算4的阶乘(数组数),我有24可能的排列组合0,1,2,3
我想知道是否有办法计算所有这些可能的排列,并将它们放在一个单独的数组中。例如,给定上面的数字{0,1,2,3},结果排列如下:
0123,0132,0213,0231,0312,0321,
1023,1032,1203,1230,1302,1320,
2013,2031,2103 ,2130,2301,2310,
3012,3021,3102,3120,3201,3210
任何帮助,非常感谢。非常感谢!
我正在寻找代码,但我设法弄清楚:)如果有人需要它,代码如下:
static NSMutableArray * results;
void doPermute(NSMutableArray * input,NSMutableArray * output,NSMutableArray * used,int size,int level){
if(size == level){
NSString * word = [输出componentsJoinedByString:@];
[results addObject:word];
return;
}
++ ++;
$ b为(int i = 0; i< input.count; i ++){
if([used [i] boolValue]){
continue;
}
used [i] = [NSNumber numberWithBool:YES];
[output addObject:input [i]];
doPermute(输入,输出,已用,大小,等级);
used [i] = [NSNumber numberWithBool:NO];
[output removeLastObject];
NSArray * getPermutations(NSString * input,int size){
results = [[NSMutableArray alloc] init];
NSMutableArray * chars = [[NSMutableArray alloc] init];
$ b for(int i = 0; i< [input length]; i ++){
NSString * ichar = [NSString stringWithFormat:@%c,[input characterAtIndex:ⅰ]];
[chars addObject:ichar];
NSMutableArray * output = [[NSMutableArray alloc] init];
NSMutableArray * used = [[NSMutableArray alloc] init];
(int i = 0; i [使用的addObject:[NSNumber numberWithBool:NO]];
doPermute(chars,output,used,size,0);
返回结果;
$ / code>
使用
getPermutations(input,size)
获取一个存储了排列的NSArray。 b
$ b
例如:
NSLog(@%@,getPermutations(@0123 ,4));
//控制台记录
结果:(
0123,
0132,
0213,
0231,
0312,
0321,
1023,
1032,
1203,
1230,
1302,
1320,
2013,
2031,
2103,
2130,
2301,
2310,
3012,
3021,
3102,
3120 ,
3201,
3210
)
我现在:)
I have an NSArray with the numbers {0,1,2,3}
Calculating the factorial of 4 (the count of the array), I have 24 possible permutations of 0,1,2,3
I would like to know if there is a way to calculate all of these possible permutations and place them in a separate array.
For example, given the numbers above, {0,1,2,3}, the resulting permutations would be:
0123, 0132, 0213, 0231, 0312, 0321,
1023, 1032, 1203, 1230, 1302, 1320,
2013, 2031, 2103, 2130, 2301, 2310,
3012, 3021, 3102, 3120, 3201, 3210
Any help is greatly appreciated. Thank you so much!
I was looking for code, but I managed to figure it out :) If anyone else needs it, the code is as follows:
static NSMutableArray *results;
void doPermute(NSMutableArray *input, NSMutableArray *output, NSMutableArray *used, int size, int level) {
if (size == level) {
NSString *word = [output componentsJoinedByString:@""];
[results addObject:word];
return;
}
level++;
for (int i = 0; i < input.count; i++) {
if ([used[i] boolValue]) {
continue;
}
used[i] = [NSNumber numberWithBool:YES];
[output addObject:input[i]];
doPermute(input, output, used, size, level);
used[i] = [NSNumber numberWithBool:NO];
[output removeLastObject];
}
}
NSArray *getPermutations(NSString *input, int size) {
results = [[NSMutableArray alloc] init];
NSMutableArray *chars = [[NSMutableArray alloc] init];
for (int i = 0; i < [input length]; i++) {
NSString *ichar = [NSString stringWithFormat:@"%c", [input characterAtIndex:i]];
[chars addObject:ichar];
}
NSMutableArray *output = [[NSMutableArray alloc] init];
NSMutableArray *used = [[NSMutableArray alloc] init];
for (int i = 0; i < chars.count; i++) {
[used addObject:[NSNumber numberWithBool:NO]];
}
doPermute(chars, output, used, size, 0);
return results;
}
use
getPermutations(input, size)
to get an NSArray with the permutations stored.
For Example:
NSLog(@"%@", getPermutations(@"0123", 4));
//console log
RESULTS: (
0123,
0132,
0213,
0231,
0312,
0321,
1023,
1032,
1203,
1230,
1302,
1320,
2013,
2031,
2103,
2130,
2301,
2310,
3012,
3021,
3102,
3120,
3201,
3210
)
It's working perfect for me now :)
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