计算最大公约数

- (void)viewDidLoad {
    [super viewDidLoad];
    NSInteger num = [self calculatemaxNumberWithM:5 N:7];
    NSLog(@"最大公约数是:%ld", (long)num);
}

// 计算最大公约数
- (NSInteger)calculatemaxNumberWithM:(NSInteger)m N:(NSInteger)n {
    NSInteger n1 = labs(n);
    NSInteger m1 = labs(m);
    while(m1 > 0) {
        NSInteger c = n1 % m1;
        n1 = m1;
        m1 = c;
    }
    return n1;
}