Как насчет этого?
NSArray *randomNumbers = [[NSArray alloc] initWithObjects:@"0",@"1",@"1",@"2",nil];
NSMutableDictionary *occurenceDict = [[NSMutableDictionary alloc] init];
for (NSString *number in randomNumbers)
{
if ([occurenceDict objectForKey:number] == nil) {
[occurenceDict setValue:[NSNumber numberWithInt:[number intValue]] forKey:number];
int occOfNum = 0;
for (int i = 0; i < [randomNumbers count]; i++) {
NSString *currentNumber = [randomNumbers objectAtIndex:i];
if ([currentNumber compare:number] == NSOrderedSame) {
occOfNum++;
}
}
[occurenceDict setValue:[NSNumber numberWithInt:occOfNum] forKey:number];
}
}
for (NSString *key in occurenceDict) {
NSString *occurrences = [occurenceDict objectForKey:key];
NSLog(@"Number %d is contained %d times", [key intValue], [occurrences intValue]);
}
[randomNumbers release];
[occurenceDict release];
Вывод:
Number 0 is contained 1 times
Number 1 is contained 2 times
Number 2 is contained 1 times
Редактировать: Incase Вы хотитеЧтобы узнать, как это работает, вот та же версия, но с комментариями, чтобы помочь вам понять это:
// Create array with the numbers that we have randomly generated
NSArray *randomNumbers = [[NSArray alloc] initWithObjects:@"0",@"1",@"1",@"2",nil];
NSMutableDictionary *occurenceDict = [[NSMutableDictionary alloc] init];
for (NSString *number in randomNumbers)
{
// If this number has not been added to the dictionary
if ([occurenceDict objectForKey:number] == nil) {
// Add it
[occurenceDict setValue:[NSNumber numberWithInt:[number intValue]] forKey:number];
// Find how many times the number occurs with the "randomNumbers" array
int occOfNum = 0;
for (int i = 0; i < [randomNumbers count]; i++) {
NSString *currentNumber = [randomNumbers objectAtIndex:i];
if ([currentNumber compare:number] == NSOrderedSame) {
// We found this number at this index, so increment the found count
occOfNum++;
}
}
// Save the number of times which "number" occurs in the dictionary for later
[occurenceDict setValue:[NSNumber numberWithInt:occOfNum] forKey:number];
}
}
// Iterate through all items in the dictionary and print out the result
for (NSString *key in occurenceDict) {
NSString *occurrences = [occurenceDict objectForKey:key];
NSLog(@"Number %d is contained %d", [key intValue], [occurrences intValue]);
}
// Release alloc'ed memory
[randomNumbers release];
[occurenceDict release];