新手求问这段代码有内存泄漏吗？

- (NSString *) getRandomWord:(int)count{
    int nextNum = -1;
    NSStringEncoding gbkEncoding =CFStringConvertEncodingToNSStringEncoding(kCFStringEncodingGB_18030_2000);
    NSString *result = [[NSString alloc] init];

    for (int i = 0; i < count; i++) {
        @autoreleasepool {
            //  [0, 100)之间的随机数
            nextNum = arc4random() % 100;
            if (nextNum % 4 == 0) {
                int heightPos = 176 + arc4random() % 39;
                int lowPos = 161 + arc4random() % 93;
                Byte wordBytes[2] = {(Byte)heightPos, (Byte)lowPos};
                NSString *oneWord = [[NSString alloc] initWithBytes:wordBytes length:2 encoding:gbkEncoding];
                result = [result stringByAppendingString:oneWord];
            }else if (nextNum % 4 == 1){
                char c = 65 + arc4random() % 26;
                result = [result stringByAppendingFormat:@"%c", c];
            }else if (nextNum % 4 == 2){
                char c = 97 + arc4random() % 26;
                result = [result stringByAppendingFormat:@"%c", c];
            }else{
                int num = 1 + arc4random() % 10;
                result = [result stringByAppendingFormat:@"%d", num];
            }
        }
    }

    return result;
}