[已解决]理解别人代码的时候有两行看不太懂什么意思

Daniel_Zhang

1. own_chunk_size = (number_of_elements >= chunk_size*(rank_of_process + 1)) ? chunk_size : (number_of_elements - chunk_size*rank_of_process);

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和

1. int received_chunk_size= (number_of_elements>= chunk_size* (rank_of_process + 2 * step))? (chunk_size * step): (number_of_elements- chunk_size* (rank_of_process + step));

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有没有大佬能帮忙简化成 if else 的形式

主要就是不明白 '?' 和 ':' 在这里面起到的作用,谢谢!

最佳答案

月排行榜 / 总排行榜

人造人

2021-9-28 07:29:51

1.     //own_chunk_size = (number_of_elements >= chunk_size*(rank_of_process + 1)) ? chunk_size : (number_of_elements - chunk_size*rank_of_process);
   
2.     if(number_of_elements >= chunk_size*(rank_of_process + 1))
   
3.     {
   
4.         own_chunk_size = chunk_size;
   
5.     }
   
6.     else
   
7.     {
   
8.         own_chunk_size = number_of_elements - chunk_size*rank_of_process;
   
9.     }
   
10. 
    
11.     //int received_chunk_size= (number_of_elements>= chunk_size* (rank_of_process + 2 * step))? (chunk_size * step): (number_of_elements- chunk_size* (rank_of_process + step));
    
12.     int received_chunk_size;
    
13.     if(number_of_elements>= chunk_size* (rank_of_process + 2 * step))
    
14.     {
    
15.         received_chunk_size = chunk_size * step;
    
16.     }
    
17.     else
    
18.     {
    
19.         received_chunk_size = number_of_elements- chunk_size* (rank_of_process + step);
    
20.     }
    

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跳转到最佳答案楼层

人造人

1.     //own_chunk_size = (number_of_elements >= chunk_size*(rank_of_process + 1)) ? chunk_size : (number_of_elements - chunk_size*rank_of_process);
   
2.     if(number_of_elements >= chunk_size*(rank_of_process + 1))
   
3.     {
   
4.         own_chunk_size = chunk_size;
   
5.     }
   
6.     else
   
7.     {
   
8.         own_chunk_size = number_of_elements - chunk_size*rank_of_process;
   
9.     }
   
10. 
    
11.     //int received_chunk_size= (number_of_elements>= chunk_size* (rank_of_process + 2 * step))? (chunk_size * step): (number_of_elements- chunk_size* (rank_of_process + step));
    
12.     int received_chunk_size;
    
13.     if(number_of_elements>= chunk_size* (rank_of_process + 2 * step))
    
14.     {
    
15.         received_chunk_size = chunk_size * step;
    
16.     }
    
17.     else
    
18.     {
    
19.         received_chunk_size = number_of_elements- chunk_size* (rank_of_process + step);
    
20.     }
    

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小甲鱼的铁粉

就是三元运算符，原理是：

1. res = (条件判断语句) ? a : b

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等价于

1. if(条件判断语句):
   
2.     res = a
   
3. else:
   
4.     res = b

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第二个

1. int received_chunk_size = 0
   
2. if number_of_elements >= chunk_size * (rank_of_process + 2 * step):
   
3.     received_chunk_size = chunk_size * step
   
4. else:
   
5.     received_chunk_size = number_of_elements - chunk_size * (rank_of_process + step)
   

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小甲鱼的铁粉

昨晚熬夜到四点吗

Daniel_Zhang

人造人 发表于 2021-9-28 07:29

谢谢大佬,刚起,吃完饭研究研究

Daniel_Zhang

小甲鱼的铁粉 发表于 2021-9-28 07:30
就是三元运算符，原理是：

等价于

谢谢大佬,刚起,吃完饭研究研究.确实,熬夜到了 4 点,躺床上也睡不着,玩了会儿手机,估计 6 点才睡的吧,太难了

小伤口

Daniel_Zhang 发表于 2021-9-28 14:00
谢谢大佬,刚起,吃完饭研究研究.确实,熬夜到了 4 点,躺床上也睡不着,玩了会儿手机,估计 6 点才睡的吧,太难 ...

我以为我熬的够久了
没想到。。。。。
这是谁的部将

Daniel_Zhang

人造人 发表于 2021-9-28 07:29

谢谢大佬再次救我狗命!