Question

Helo，在不完美嵌套循环的情况下，我对内循环的定义有点困惑。考虑一下这段代码

for (i = 0; i < n; ++i)
{
   for (j = 0; j <= i - 1; ++j)
        /*some statement*/
    p[i] = 1.0 / sqrt (x);
   for (j = i + 1; j < n; ++j)
   {
       x = a[i][j];
       for (k = 0; k <= i - 1; ++k)
          /*some statement*/
       a[j][i] = x * p[i];
   }
}

这里，我们在同一嵌套级别中有两个循环。但是，在从j + 1开始迭代“j”的第二个循环中，还有另一个嵌套级别。考虑整个循环结构，这是代码中最内层的循环？

Answer 1

j个循环同样嵌套在i内，k是最里面的循环

Answer 2

我会说k是最里面的循环，因为如果你计算从外部到达它所需的循环数，它就是三个循环，这是所有四个循环中最多的循环在你的代码中循环。

Answer 3

大声笑我不知道如何解释这个，所以我会尽我所能，我推荐使用debugger！它可能对你有所帮助，你甚至都不会知道

for (i = 0; i < n; ++i)
{
   //Goes in here first.. i = 0..
   for (j = 0; j <= i - 1; ++j) {
        //Goes here second..
        //Goes inside here and gets stuck until j is greater then (i- 1) (right now i = 0)
        //So (i-1) = -1 so it does this only once.
        /*some statement*/
    p[i] = 1.0 / sqrt (x);
   }
   for (j = i + 1; j < n; ++j)
   {
      //Goes sixth here.. etc.. .. 
      //when this is done.. goes to loop for (i = 0; i < n; ++i)

      //Goes here third and gets stuck
      //j = i which is 0 + 1.. so, j == 1
      //keeps looping inside this loop until j is greater then n.. idk what is n..
      //Can stay here until it hits n.. which could be a while.
       x = a[i][j];
       for (k = 0; k <= i - 1; ++k) {
           //Goes in here fourth until k > (i-1).. i is still 0..
           //So (i-1) = -1 so it does this only once
          /*some statement*/
       a[j][i] = x * p[i];
      }
      //Goes here fifth.. which goes.... to this same loop!
   }
}

什么是不完美嵌套循环中的Innermost循环？

3 个答案: