从给定的数组形成一个螺旋矩阵
给定一个数组，任务是形成一个螺旋矩阵
例子：
Input:
arr[] = { 1, 2, 3, 4, 5,
6, 7, 8, 9, 10,
11, 12, 13, 14, 15, 16 };
Output:
1 2 3 4
12 13 14 5
11 16 15 6
10 9 8 7
Input:
arr[] = { 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18 };
Output:
1 2 3 4 5 6
14 15 16 17 18 7
13 12 11 10 9 8方法：这个问题正好是这个问题的相反“以螺旋形式打印给定的矩阵”。这样做的方法是：
- 遍历给定的数组并一一选取每个元素。
- 按螺旋矩阵顺序填充每个元素。
- 螺旋矩阵顺序在 4 个循环的帮助下保持不变——左、右、上和下。
- 每个循环在螺旋矩阵中打印其相应的行/列。
下面是上述方法的实现：
C++
// C++ program to form a Spiral Matrix
// from the given Array
#include
using namespace std;
#define R 3
#define C 6
// Function to form the spiral matrix
void formSpiralMatrix(int arr[], int mat[R][C])
{
int top = 0,
bottom = R - 1,
left = 0,
right = C - 1;
int index = 0;
while (1) {
if (left > right)
break;
// print top row
for (int i = left; i <= right; i++)
mat[top][i] = arr[index++];
top++;
if (top > bottom)
break;
// print right column
for (int i = top; i <= bottom; i++)
mat[i][right] = arr[index++];
right--;
if (left > right)
break;
// print bottom row
for (int i = right; i >= left; i--)
mat[bottom][i] = arr[index++];
bottom--;
if (top > bottom)
break;
// print left column
for (int i = bottom; i >= top; i--)
mat[i][left] = arr[index++];
left++;
}
}
// Function to print the spiral matrix
void printSpiralMatrix(int mat[R][C])
{
for (int i = 0; i < R; i++) {
for (int j = 0; j < C; j++)
cout << mat[i][j] << " ";
cout << '\n';
}
}
// Driver code
int main()
{
int arr[]
= { 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18 };
int mat[R][C];
formSpiralMatrix(arr, mat);
printSpiralMatrix(mat);
return 0;
} Java
// Java program to form a Spiral Matrix
// from the given Array
class GFG
{
static final int R = 3 ;
static final int C = 6;
// Function to form the spiral matrix
static void formSpiralMatrix(int arr[], int mat[][])
{
int top = 0,
bottom = R - 1,
left = 0,
right = C - 1;
int index = 0;
while (true)
{
if (left > right)
break;
// print top row
for (int i = left; i <= right; i++)
mat[top][i] = arr[index++];
top++;
if (top > bottom)
break;
// print right column
for (int i = top; i <= bottom; i++)
mat[i][right] = arr[index++];
right--;
if (left > right)
break;
// print bottom row
for (int i = right; i >= left; i--)
mat[bottom][i] = arr[index++];
bottom--;
if (top > bottom)
break;
// print left column
for (int i = bottom; i >= top; i--)
mat[i][left] = arr[index++];
left++;
}
}
// Function to print the spiral matrix
static void printSpiralMatrix(int mat[][])
{
for (int i = 0; i < R; i++)
{
for (int j = 0; j < C; j++)
System.out.print(mat[i][j] + " ");
System.out.println();
}
}
// Driver code
public static void main (String[] args)
{
int arr[] = { 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18 };
int mat[][] = new int[R][C];
formSpiralMatrix(arr, mat);
printSpiralMatrix(mat);
}
}
// This code is contributed by kanugargngPython3
# Python program to form a Spiral Matrix
# from the given Array
R = 3 ;
C = 6;
# Function to form the spiral matrix
def formSpiralMatrix(arr, mat):
top = 0;
bottom = R - 1;
left = 0;
right = C - 1;
index = 0;
while (True):
if(left > right):
break;
# prtop row
for i in range(left, right + 1):
mat[top][i] = arr[index];
index += 1;
top += 1;
if (top > bottom):
break;
# prright column
for i in range(top, bottom+1):
mat[i][right] = arr[index];
index += 1;
right -= 1;
if (left > right):
break;
# prbottom row
for i in range(right, left-1, -1):
mat[bottom][i] = arr[index];
index += 1;
bottom -= 1;
if (top > bottom):
break;
# prleft column
for i in range(bottom, top-1, -1):
mat[i][left] = arr[index];
index += 1;
left += 1;
# Function to prthe spiral matrix
def printSpiralMatrix(mat):
for i in range(R):
for j in range(C):
print(mat[i][j],end= " ");
print();
# Driver code
if __name__ == '__main__':
arr = [ 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18 ];
mat= [[0 for i in range(C)] for j in range(R)];
formSpiralMatrix(arr, mat);
printSpiralMatrix(mat);
# This code contributed by PrinciRaj1992C#
// C# program to form a Spiral Matrix
// from the given Array
using System;
class GFG
{
static readonly int R = 3;
static readonly int C = 6;
// Function to form the spiral matrix
static void formSpiralMatrix(int []arr,
int [,]mat)
{
int top = 0,
bottom = R - 1,
left = 0,
right = C - 1;
int index = 0;
while (true)
{
if (left > right)
break;
// print top row
for (int i = left; i <= right; i++)
mat[top, i] = arr[index++];
top++;
if (top > bottom)
break;
// print right column
for (int i = top; i <= bottom; i++)
mat[i, right] = arr[index++];
right--;
if (left > right)
break;
// print bottom row
for (int i = right; i >= left; i--)
mat[bottom, i] = arr[index++];
bottom--;
if (top > bottom)
break;
// print left column
for (int i = bottom; i >= top; i--)
mat[i, left] = arr[index++];
left++;
}
}
// Function to print the spiral matrix
static void printSpiralMatrix(int [,]mat)
{
for (int i = 0; i < R; i++)
{
for (int j = 0; j < C; j++)
Console.Write(mat[i, j] + " ");
Console.WriteLine();
}
}
// Driver code
public static void Main (String[] args)
{
int []arr = { 1, 2, 3, 4, 5, 6,
7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18 };
int [,]mat = new int[R, C];
formSpiralMatrix(arr, mat);
printSpiralMatrix(mat);
}
}
// This code is contributed by 29AjayKumarJavascript
输出：
1 2 3 4 5 6
14 15 16 17 18 7
13 12 11 10 9 8如果您希望与专家一起参加现场课程，请参阅DSA 现场工作专业课程和学生竞争性编程现场课程。