排序第二阵列后阵列获取索引对象的无重复

Question

我在这里的两个不同的阵列

[ 
    "21:55", 
    "21:55", 
    "21:55", 
    "22:00", 
    "21:55" 
] 

我使用以上两个数组分选这样下面的代码，

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; 
     [dateFormatter setDateFormat:@"HH:mm"]; 

     NSArray *sortedTimes = [timeArraySorting sortedArrayUsingComparator:^NSComparisonResult(NSString *obj1, NSString *obj2) 
     { 
      NSDate *date1 = [dateFormatter dateFromString:obj1]; 
      NSDate *date2 = [dateFormatter dateFromString:obj2]; 
      return [date1 compare:date2]; 
     }]; 
     NSLog(@"Start sortedTimes= %@",sortedTimes); 

像这样，

sortedTimes = [ 
     "21:55", 
     "21:55", 
     "21:55", 
     "21:55", 
     "22:00" 
    ] 

但我需要比较第二个数组与第一个数组，以获得第一个数组的索引。但在这里我得到重复这样的，

[ 
    0, 
    0, 
    0, 
    0, 
    3 
] 

，但我需要这样，

[ 
    0, 
    1, 
    2, 
    4, 
    3 
] 

能否请你建议我怎样才能解决这个问题？ 谢谢。

Answer 1

的一种方法是添加索引到原来的数组和排序这些呢，用字符串数据一起......

// data from the OP 
NSArray *timeArraySorting = @[ 
        @"21:55", 
        @"21:55", 
        @"21:55", 
        @"22:00", 
        @"21:55" 
        ]; 

// add index data to it, so it has the form: 
// @[ [ @"21:55", @0], [ @"21:55", @1], ... 
NSMutableArray *indexedTimeArray = [@[] mutableCopy]; 
for (int i=0; i<timeArraySorting.count; i++) { 
    [indexedTimeArray addObject: @[timeArraySorting[i], @(i)] ]; 
} 

NSDateFormatter *dateFormatter = [[NSDateFormatter alloc] init]; 
[dateFormatter setDateFormat:@"HH:mm"]; 

// sort that indexed data 
NSArray *sortedTimes = [indexedTimeArray sortedArrayUsingComparator:^NSComparisonResult(NSArray *obj1, NSArray *obj2) { 
    NSDate *date1 = [dateFormatter dateFromString:obj1[0]]; 
    NSDate *date2 = [dateFormatter dateFromString:obj2[0]]; 
    return [date1 compare:date2]; 
}]; 
NSLog(@"Start sortedTimes= %@",sortedTimes); 

输出看起来是这样的：

Start sortedTimes= (
    (
    "21:55", 
    0 
), 
    (
    "21:55", 
    1 
), 
    (
    "21:55", 
    2 
), 
    (
    "21:55", 
    4 
), 
    (
    "22:00", 
    3 
) 
) 

运行通过阵列皮卡排序结果和排序的指标...

NSMutableArray *result = [@[] mutableCopy]; 
NSMutableArray *indexes = [@[] mutableCopy]; 

for (NSArray *a in sortedTimes) { 
    [result addObject:a[0]]; 
    [indexes addObject:a[1]]; 
} 

NSLog(@"result is %@", result); 
NSLog(@"indexes is %@", indexes); 

测试相匹配的OP期望的结果。