从点开始以螺旋形式打印矩阵 · GeeksForGeeks 中文系列教程

# 从点开始以螺旋形式打印矩阵 > 原文： [https://www.geeksforgeeks.org/print-matrix-spiral-form-starting-point/](https://www.geeksforgeeks.org/print-matrix-spiral-form-starting-point/) 给定大小为 n * m 的矩阵和点 P（c，r）。从点 P 开始以螺旋形式（顺时针）打印矩阵。 **示例**： ``` Input : mat[][] = {{1 2 3}, {4 5 6}, {7 8 9}} Point P = (0, 2) Output : 3 6 5 2 9 8 7 4 1 The starting point is top left which is 3. ``` 这个问题主要是[以螺旋形式](https://www.geeksforgeeks.org/print-a-given-matrix-in-spiral-form/)打印矩阵的扩展。 ## C++ ```cpp // C++ program to print a matrix in spiral // form. #include <iostream> using namespace std; const int MAX = 100; void printSpiral(int mat[][MAX], int r, int c) { int i, a = 0, b = 2; int low_row = (0 > a) ? 0 : a; int low_column = (0 > b) ? 0 : b - 1; int high_row = ((a + 1) >= r) ? r - 1 : a + 1; int high_column = ((b + 1) >= c) ? c - 1 : b + 1; while ((low_row > 0 - r && low_column > 0 - c)) { for (i = low_column + 1; i <= high_column && i < c && low_row >= 0; ++i) cout << mat[low_row][i] << " "; low_row -= 1; for (i = low_row + 2; i <= high_row && i < r && high_column < c; ++i) cout << mat[i][high_column] << " "; high_column += 1; for (i = high_column - 2; i >= low_column && i >= 0 && high_row < r; --i) cout << mat[high_row][i] << " "; high_row += 1; for (i = high_row - 2; i > low_row && i >= 0 && low_column >= 0; --i) cout << mat[i][low_column] << " "; low_column -= 1; } cout << endl; } // Driver code int main() { int mat[][MAX] = { { 1, 2, 3 }, { 4, 5, 6 }, { 7, 8, 9 } }; int r = 3, c = 3; printSpiral(mat, r, c); } ``` ## Java ```java // Java program to print a // matrix in spiral form import java.io.*; class GFG { static void printSpiral(int [][]mat, int r, int c) { int i, a = 0, b = 2; int low_row = (0 > a) ? 0 : a; int low_column = (0 > b) ? 0 : b - 1; int high_row = ((a + 1) >= r) ? r - 1 : a + 1; int high_column = ((b + 1) >= c) ? c - 1 : b + 1; while ((low_row > 0 - r && low_column > 0 - c)) { for (i = low_column + 1; i <= high_column && i < c && low_row >= 0; ++i) System.out.print (mat[low_row][i] + " "); low_row -= 1; for (i = low_row + 2; i <= high_row && i < r && high_column < c; ++i) System.out.print(mat[i][high_column] + " "); high_column += 1; for (i = high_column - 2; i >= low_column && i >= 0 && high_row < r; --i) System.out.print(mat[high_row][i] + " "); high_row += 1; for (i = high_row - 2; i > low_row && i >= 0 && low_column >= 0; --i) System.out.print(mat[i][low_column] +" "); low_column -= 1; } System.out.println(); } // Driver code static public void main (String[] args) { int [][]mat = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; int r = 3, c = 3; // Function calling printSpiral(mat, r, c); } } // This code is contributed by vt_m. ``` ## Python 3 ``` # Python3 program to print a matrix # in spiral form. MAX = 100 def printSpiral(mat, r, c): a = 0 b = 2 low_row = 0 if (0 > a) else a low_column = 0 if (0 > b) else b - 1 high_row = r-1 if ((a + 1) >= r) else a + 1 high_column = c-1 if ((b + 1) >= c) else b + 1 while ((low_row > 0 - r and low_column > 0 - c)): i = low_column + 1 while (i <= high_column and i < c and low_row >= 0): print( mat[low_row][i], end = " ") i += 1 low_row -= 1 i = low_row + 2 while (i <= high_row and i < r and high_column < c): print(mat[i][high_column], end = " ") i += 1 high_column += 1 i = high_column - 2 while (i >= low_column and i >= 0 and high_row < r): print(mat[high_row][i], end = " ") i -= 1 high_row += 1 i = high_row - 2 while (i > low_row and i >= 0 and low_column >= 0): print(mat[i][low_column], end = " ") i -= 1 low_column -= 1 print() # Driver code if __name__ == "__main__": mat = [[ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8, 9 ]] r = 3 c = 3 printSpiral(mat, r, c) # This code is contributed by ita_c ``` ## C# ```cs // C# program to print a // matrix in spiral form using System; class GFG { static void printSpiral(int [,]mat, int r, int c) { int i, a = 0, b = 2; int low_row = (0 > a) ? 0 : a; int low_column = (0 > b) ? 0 : b - 1; int high_row = ((a + 1) >= r) ? r - 1 : a + 1; int high_column = ((b + 1) >= c) ? c - 1 : b + 1; while ((low_row > 0 - r && low_column > 0 - c)) { for (i = low_column + 1; i <= high_column && i < c && low_row >= 0; ++i) Console.Write (mat[low_row,i] + " "); low_row -= 1; for (i = low_row + 2; i <= high_row && i < r && high_column < c; ++i) Console.Write(mat[i,high_column] + " "); high_column += 1; for (i = high_column - 2; i >= low_column && i >= 0 && high_row < r; --i) Console.Write(mat[high_row,i] + " "); high_row += 1; for (i = high_row - 2; i > low_row && i >= 0 && low_column >= 0; --i) Console.Write(mat[i,low_column] +" "); low_column -= 1; } Console.WriteLine(); } // Driver code static public void Main () { int [,]mat = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; int r = 3, c = 3; // Function calling printSpiral(mat, r, c); } } // This code is contributed by vt_m. ``` ## PHP ```php <?php // PHP program to print a // matrix in spiral form. $MAX = 100; function printSpiral($mat, $r, $c) { global $MAX; $i; $a = 0; $b = 2; $low_row = (0 > $a) ? 0 : $a; $low_column = (0 > $b) ? 0 : $b - 1; $high_row = (($a + 1) >= $r) ? $r - 1 : $a + 1; $high_column = (($b + 1) >= $c) ? $c - 1 : $b + 1; while (($low_row > 0 - $r && $low_column > 0 - $c)) { for ($i = $low_column + 1; $i <= $high_column && $i < $c && $low_row >= 0; ++$i) echo $mat[$low_row][$i], " "; $low_row -= 1; for ($i = $low_row + 2; $i <= $high_row && $i < $r && $high_column < $c; ++$i) echo $mat[$i][$high_column] , " "; $high_column += 1; for ($i = $high_column - 2; $i >= $low_column && $i >= 0 && $high_row < $r; --$i) echo $mat[$high_row][$i] , " "; $high_row += 1; for ($i = $high_row - 2; $i > $low_row && $i >= 0 && $low_column >= 0; --$i) echo $mat[$i][$low_column] , " "; $low_column -= 1; } echo "\n"; } // Driver code $mat = array(array(1, 2, 3), array(4, 5, 6), array(7, 8, 9)); $r = 3; $c = 3; printSpiral($mat, $r, $c); // This code is contributed by aj_36 ?> ``` **输出**： ``` 3 6 5 2 9 8 7 4 1 ```