如何将此嵌套迭代转换为递归解决方案? [英] How do I convert this nested iteration to a recursive solution?
本文介绍了如何将此嵌套迭代转换为递归解决方案?的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我写了一个代码,计算矩阵中相邻元素的总和,并将它们存储到另一个 sum_mat
的矩阵中。我需要这个代码的相同结果,但在递归解决方案,我不知道如何将嵌套循环转换为递归。
I have this code I wrote that calculates the sum of neighboring elements in a matrix and stores them into another matrix called sum_mat
. I need the same result of this code but in a recursive solution and I don't know how to convert nested loops into recursion.
void calculate_result(int n,int mat[100][100])
{
//calculates an (n-1)x(n-1) matrix in which each element the sum of 4
// neighboring elements in the original matrix.
int sum_mat[100][100];
for(int i=1;i<=n-1;i++)
{
for(int j=1;j<=n-1;j++)
sum_mat[i][j]=mat[i][j]+mat[i+1][j]+mat[i][j+1]+mat[i+1][j+1];
}
}
结果示例:
n=3
| 1 2 3 | sum_mat=| 8 9 |
mat=| 2 3 1 | --> | 11 7 |
| 5 1 2 |
推荐答案
尾递归过程和递归发起者:
You can convert any "for i" loop into a tail recursive procedure and a recursion initiator:
// loop A
for (i = 1; i <= n; i++) {
// body code
}
p>
becomes
void for_loop_A_impl(int i, ...params needed by the body...) {
if (i > n) return;
// body code
for_loop_A_impl(i + 1,...params needed by the body...);
}
void for_loop_A(...params needed by the body code...) {
for_loop_A_impl(1, ...params needed by the body code...);
}
现在调用 for_loop_A
代替循环本身。继续转换,直到所有的循环都消失了。
Now call for_loop_A
in place of the loop itself. Keep transforming like this until all the loops are gone.
这篇关于如何将此嵌套迭代转换为递归解决方案?的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文