剑指offer-面试题20 顺时针打印矩阵

//输入一个矩阵,按照从外向里依次顺时针打印每个数字
#include<iostream>
using namespace std;
void PrintOneCircle(int **Matrix, int columns, int rows, int start)
{
int startX = start;
int startY = start;
int endX = columns-1-start;    //y坐标末尾
int endY = rows-1-start;        //x坐标末尾
//打印第一行
for(int i = startY; i <= endY; ++i)
{
cout<<Matrix[startX][i]<<", ";
}
//打印右边一列,要求至少有两列
if(endX > startX)
{
for(int i =startX+1; i <= endX; ++i)
{
cout<<Matrix[i][endY]<<", ";
}
}
//打印下面一行,要求至少要有两列,并且至少两行
if(endX > startX && endY > startY)
{
for(int i = endY-1; i >= startY; --i)
{
cout<<Matrix[endX][i]<<", ";
}
}
//打印左边一列,要求至少两列并且至少三行
if(endY > startY && endX > startX+1)
{
for(int i = endX-1; i >= startX+1; --i)
{
cout<<Matrix[i][startY]<<", ";
}
}
}
//不知道具体行列个数的二维数组只能以指针的指针的形式传参
void CirclePrintMatrix(int **Matrix, int columns, int rows)
{
if(Matrix == NULL || columns<=0 || rows <= 0)
return;
int start = 0;
while(2*start < columns && 2*start < rows)
{
PrintOneCircle(Matrix, columns, rows, start);
++start;
}
}
int main()
{
int M[4][4] = {1, 2, 3, 4,5,6,7,8,9,10,11,12,13,14,15,16};
int **p = new int *[4];
for(int i = 0; i < 4; ++i)
{
p[i] = M[i];
}
CirclePrintMatrix(p ,4, 4);
}