iphone - 如何从另一个已排序的数组中获取索引数组？

Question

我想按数组的对象对数组进行排序，然后获取索引，如下所示:

NSMutableArray *myArray = [[NSMutableArray alloc] initWithObjects: @"3", @"2", @"1", @"0", @"1", @"2", nil];

我希望对象的索引按升序排列。在这里，因为最低值的索引为 3，所以索引将为:3、2、4、1、5、0 或类似的值。

有什么想法吗？

谢谢!

Answer 1

这就是我最终所做的:

//Create a mutable array of the indexes in the myArray (just a list from 0...n)

NSMutableArray *indexes = [[NSMutableArray alloc] init];

for (int i = 0; i < myArray.count; i++){
    [indexes addObject: [NSNumber numberWithInteger:i]];
}

//Create a dictionary with myArray as the objects and the indexes as the keys
NSDictionary *tempDictionary = [NSDictionary dictionaryWithObjects:myArray forKeys:indexes];

//Create an array of myArray's keys, in the order they would be in if they were sorted by the values 
NSArray *sorted = [tempDictionary keysSortedByValueUsingSelector: @selector(compare:)];