好尴尬，现在还在啃冒泡排序

- (void)sortArray{
    NSMutableArray *sortArray = [NSMutableArray arrayWithArray:@[@(10), @(3), @(7), @(2), @(8), @(4), @(11), @(4), @(9)]];
    NSLog(@"排序前：%@", sortArray);
    for (int i = 0; i < sortArray.count-1; i ++) {
        for (int j = 0; j < sortArray.count-1-i; j ++) {
            NSInteger left = [sortArray[j] integerValue];
            NSInteger right = [sortArray[j+1] integerValue];
            if (left>right) {
                [sortArray exchangeObjectAtIndex:j withObjectAtIndex:j+1];
            }
            NSLog(@"\ni=%d\tj=%d\n%@", i, j, sortArray);
        }
    }
    NSLog(@"排序后：%@", sortArray);
}