Hamming

gistfile1.m

#import "Hamming.h"

@implementation Hamming

+ (NSUInteger) compute:(NSString *)firstString against:(NSString *)secondString {
    int hammingDistance = 0;
    if ([firstString length] <= [secondString length]) {
        hammingDistance = (int)[self loopForStringBeginningWithShort:firstString withLong:secondString];
    } else {
        hammingDistance = (int)[self loopForStringBeginningWithShort:secondString withLong:firstString];
    }
    return hammingDistance;
}

+ (NSUInteger) loopForStringBeginningWithShort:(NSString *)shortStr withLong:(NSString *)longStr {
    int distance = 0;
    for(int i = 0; i < [shortStr length]; i++) {
        NSString* a = [NSString stringWithFormat:@"%c", [shortStr characterAtIndex:i]];
        NSString* b = [NSString stringWithFormat:@"%c", [longStr characterAtIndex:i]];
        if (![a isEqual:b]) {
            distance++;
        }
    }
    return (NSUInteger)distance;
}

@end