# 以防螺旋形式打印矩阵 > 原文： [https://www.geeksforgeeks.org/print-matrix-antispiral-form/](https://www.geeksforgeeks.org/print-matrix-antispiral-form/) 给定 2D 数组，任务是以反螺旋形式打印矩阵： **示例**： [](https://media.geeksforgeeks.org/wp-content/uploads/spiral1.jpg) 输出：16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 ``` Input : arr[][4] = {1, 2, 3, 4 5, 6, 7, 8 9, 10, 11, 12 13, 14, 15, 16}; Output : 10 11 7 6 5 9 13 14 15 16 12 8 4 3 2 1 Input :arr[][6] = {1, 2, 3, 4, 5, 6 7, 8, 9, 10, 11, 12 13, 14, 15, 16, 17, 18}; Output : 11 10 9 8 7 13 14 15 16 17 18 12 6 5 4 3 2 1 ``` 想法很简单，我们以螺旋形式遍历矩阵[，并将所有遍历的元素放入堆栈中。 最后从堆栈中逐一列出并打印它们。](https://www.geeksforgeeks.org/print-a-given-matrix-in-spiral-form/) ## C++ ```cpp // C++ program to print matrix in anti-spiral form #include <bits/stdc++.h> using namespace std; #define R 4 #define C 5 void antiSpiralTraversal(int m, int n, int a[R][C]) {     int i, k = 0, l = 0;     /*  k - starting row index         m - ending row index         l - starting column index         n - ending column index         i - iterator  */     stack<int> stk;     while (k <= m && l <= n)     {         /* Print the first row from the remaining rows */         for (i = l; i <= n; ++i)             stk.push(a[k][i]);         k++;         /* Print the last column from the remaining columns */         for (i = k; i <= m; ++i)             stk.push(a[i][n]);         n--;         /* Print the last row from the remaining rows */         if ( k <= m)         {             for (i = n; i >= l; --i)                 stk.push(a[m][i]);             m--;         }         /* Print the first column from the remaining columns */         if (l <= n)         {             for (i = m; i >= k; --i)                 stk.push(a[i][l]);             l++;         }     }     while (!stk.empty())     {         cout << stk.top() << " ";         stk.pop();     } } /* Driver program to test above functions */ int main() {     int mat[R][C] =     {         {1,  2,  3,  4,  5},         {6,  7,  8,  9,  10},         {11, 12, 13, 14, 15},         {16, 17, 18, 19, 20}     };     antiSpiralTraversal(R-1, C-1, mat);     return 0; } ```