旋转矩阵元素的 C++ 程序
给定一个矩阵,顺时针旋转其中的元素。
例子:
Input
1 2 3
4 5 6
7 8 9
Output:
4 1 2
7 5 3
8 9 6
For 4*4 matrix
Input:
1 2 3 4
5 6 7 8
9 10 11 12
13 14 15 16
Output:
5 1 2 3
9 10 6 4
13 11 7 8
14 15 16 12
这个想法是使用类似于以螺旋形式打印矩阵的程序的循环。从最外层开始,一个接一个地旋转所有元素环。要旋转环,我们需要执行以下操作。
1)移动顶行的元素。
2) 移动最后一列的元素。
3)移动底行的元素。
4) 移动第一列的元素。
当有内圈时,对内圈重复上述步骤。
下面是上述想法的实现。感谢 Gaurav Ahirwar 提出以下解决方案。
C++
// C++ program to rotate a matrix
#include
#define R 4
#define C 4
using namespace std;
// A function to rotate a matrix mat[][] of size R x C.
// Initially, m = R and n = C
void rotatematrix(int m, int n, int mat[R][C])
{
int row = 0, col = 0;
int prev, curr;
/*
row - Starting row index
m - ending row index
col - starting column index
n - ending column index
i - iterator
*/
while (row < m && col < n)
{
if (row + 1 == m || col + 1 == n)
break;
// Store the first element of next row, this
// element will replace first element of current
// row
prev = mat[row + 1][col];
/* Move elements of first row from the remaining rows */
for (int i = col; i < n; i++)
{
curr = mat[row][i];
mat[row][i] = prev;
prev = curr;
}
row++;
/* Move elements of last column from the remaining columns */
for (int i = row; i < m; i++)
{
curr = mat[i][n-1];
mat[i][n-1] = prev;
prev = curr;
}
n--;
/* Move elements of last row from the remaining rows */
if (row < m)
{
for (int i = n-1; i >= col; i--)
{
curr = mat[m-1][i];
mat[m-1][i] = prev;
prev = curr;
}
}
m--;
/* Move elements of first column from the remaining rows */
if (col < n)
{
for (int i = m-1; i >= row; i--)
{
curr = mat[i][col];
mat[i][col] = prev;
prev = curr;
}
}
col++;
}
// Print rotated matrix
for (int i=0; i
输出:
5 1 2 3
9 10 6 4
13 11 7 8
14 15 16 12
有关更多详细信息,请参阅有关旋转矩阵元素的完整文章!