Find first unique integer from an array

FirstUniqueInt.m

//
//  main.m
//  Algorithm
//
//  Created by Rohan Patel on 11/10/17.
//  Copyright © 2017 Rohan Patel. All rights reserved.
//

/*
       Note: I found two mistakes in the proposed solution during the interview:
 *  i) Mutable dictionary is required to be able to add elements instead of immutable dictionary.
 * ii) NSMutableDictionary/ NSDictionary does not guarantee the order of the key-value pairs. Subclassing it might be an option to achieve the ordered Dictionary list.
*/
#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        // insert code here...
        //NSLog(@"Hello, World!");
        
        NSArray *array = @[@1,@2,@3,@2,@1, @3, @7, @6];
        //NSArray *array = @[@1,@2,@3,@2,@1, @3, @7, @6, @7, @6];
        
        
       
        NSMutableDictionary *dict = [NSMutableDictionary dictionary];
        
        /* First for loop to scan the integer elements and insert them into Dictionary as key-value pairs.
         * Key = integer of an array
         * Value = Counter for occurance of particular integer
         */
        for (int i=0; i < [array count]; i++) {
            if ([dict objectForKey:array[i]]){
                long int count = [[dict objectForKey:array[i]]integerValue];
                [dict setObject:[NSNumber numberWithInt:++count] forKey:array[i]];
            }
            else{
                [dict setObject:[NSNumber numberWithInt:1] forKey:array[i]];
            }
        }
        NSLog(@"%@",dict);
        
        /* Second for loop to scan the Dictionary to look for the first unique element
         */
        
        BOOL isUniqueCharFound = NO;
        
        for (id key in dict) {
            long int value = [[dict objectForKey: key]integerValue];
            if (value == 1) {
                NSLog(@"--> %ld", [key integerValue]);
                isUniqueCharFound = YES;
                break;
            }
        }
        if (!isUniqueCharFound) {
            NSLog(@"There is not any unique integer in the array!");
        }
    }
    return 0;
}