递归和非递归打印螺旋矩阵

#include <iostream>#include <cstdlib>#include <cstring>int **matrix;int value = 1;void recursion (int row, int col, int len) // row, col代表本次左上角元素的位置, len为本次矩阵边长{if (len <= 0){return;}int i = row, j = col;while (j < col + len){matrix[i][j++] = value++;}j--;i++;while (i < row + len){matrix[i++][j] = value++;}i--;j--;while (j >= col){matrix[i][j--] = value++;}j++;i--;while (i > row){matrix[i--][j] = value++;}i++;j++;recursion(i, j, len - 2);}void no_recursion ( int n ) // n为整个矩阵的边长{int i, j, len, col, row;for (i = 0, j = 0, len = n; len > 0; ){row = i;col = j;while (j < col + len){matrix[i][j++] = value++;}j--;i++;while (i < row + len){matrix[i++][j] = value++;}i--;j--;while (j >= col){matrix[i][j--] = value++;}j++;i--;while (i > row){matrix[i--][j] = value++;}i++;j++;len = len - 2;}}int main(){int N = 7, i, j;matrix = (int**) malloc(sizeof(int*) * N);for (i = 0; i < N; i++){matrix[i] = (int*) malloc(sizeof(int) * N);memset(matrix[i], 0, sizeof(int) * N);}no_recursion(N);for (i = 0; i < N; i++){for (j = 0; j < N; j++){std::cout << matrix[i][j] << ' ';}std::cout << std::endl;}for (i = 0; i < N; i++){free(matrix[i]);}free(matrix);return 0;}