nsmutablearray - NSMutableDictionary の NSMutableArray の値を小計する方法

Question

これがハウツーであることはわかっていますが、何らかの理由で、単純な高速列挙であるべきものを複雑にしすぎています。各「数値」の「シフト長」を小計したいだけです。mm:ss を秒に変換して簡単に変換するために作成した NSObject がありますが、それについては心配していません。結果を NSMutableDictionary の別の NSArray にしたい:

{
Number = 2;
"Shift Length" = "1:30"
}, etc.

前もって感謝します...

-ポール

サンプルデータ

2013-11-24 15:58:32.677 TimeOnIce[79815:70b] _gameSheetMutableArray: (
    {
    Number = 10;
    "Shift Length" = " 1:32";
    "Time Off Ice" = "08:00";
    "Time On Ice" = "09:32";
},
    {
    Number = 11;
    "Shift Length" = " 1:34";
    "Time Off Ice" = "07:56";
    "Time On Ice" = "09:30";
},
    {
    Number = 14;
    "Shift Length" = " 1:10";
    "Time Off Ice" = "06:56";
    "Time On Ice" = "08:06";
},
    {
    Number = 15;
    "Shift Length" = " 1:10";
    "Time Off Ice" = "06:54";
    "Time On Ice" = "08:04";
},
    {
    Number = 16;
    "Shift Length" = " 1:10";
    "Time Off Ice" = "06:52";
    "Time On Ice" = "08:02";
},
    {
    Number = 2;
    "Shift Length" = " 0:22";
    "Time Off Ice" = "09:38";
    "Time On Ice" = "10:00";
},
    {
    Number = 2;
    "Shift Length" = " 1:08";
    "Time Off Ice" = "06:48";
    "Time On Ice" = "07:56";
},
    {
    Number = 20;
    "Shift Length" = " 1:10";
    "Time Off Ice" = "06:50";
    "Time On Ice" = "08:00";
},
    {
    Number = 3;
    "Shift Length" = " 0:24";
    "Time Off Ice" = "09:36";
    "Time On Ice" = "10:00";
},
    {
    Number = 4;
    "Shift Length" = " 0:26";
    "Time Off Ice" = "09:34";
    "Time On Ice" = "10:00";
},
    {
    Number = 5;
    "Shift Length" = " 0:28";
    "Time Off Ice" = "09:32";
    "Time On Ice" = "10:00";
},
    {
    Number = 6;
    "Shift Length" = " 0:30";
    "Time Off Ice" = "09:30";
    "Time On Ice" = "10:00";
},
    {
    Number = 7;
    "Shift Length" = " 1:32";
    "Time Off Ice" = "08:06";
    "Time On Ice" = "09:38";
},
    {
    Number = 8;
    "Shift Length" = " 1:32";
    "Time Off Ice" = "08:04";
    "Time On Ice" = "09:36";
},
    {
    Number = 9;
    "Shift Length" = " 1:32";
    "Time Off Ice" = "08:02";
    "Time On Ice" = "09:34";
}

編集

これを次の方法で解決できました。

NSArray *playerNumbersArray = [_gameSheetMutableArray valueForKeyPath:@"@distinctUnionOfObjects.Number"];

    for (NSString *playerNumber in playerNumbersArray)
    {
        NSPredicate *predicate = [NSPredicate predicateWithFormat:@"(Number == %@)", playerNumber];
        NSArray *playerNumbersArrayPredicate = [_gameSheetMutableArray filteredArrayUsingPredicate:predicate];

        NSNumber *shiftLength = [playerNumbersArrayPredicate valueForKeyPath:@"@sum.Shift Length"];
        NSLog(@"Player Number %@: Time on Ice: %@", playerNumber, [_convertSecondsToMMSS convertSecondstoMMSS:[shiftLength intValue]]);
    }