題目：Given amxnmatrix, if an element is 0, set its entire row and column to 0. Do it in place.
Follow up:Did you use extra space?
A straight forward solution using O(mn) space is probably a bad idea.
A simple improvement uses O(m+n) space, but still not the best solution.
Could you devise a constant space solution?
解題思路：保存行和列為0的索引，改變該行和該列上的所有數為0即可，實現代碼如下所示：
public class Solution
{
public void setZeroes(int[][] matrix)
{
int m=matrix.length; //行數
if(m==0)
return ;
int n=matrix[0].length; //列數
List a=new ArrayList(); //存放所有的行中值為0的索引
List b=new ArrayList(); //存放所有的列中值為0的索引
for (int i = 0; i < m; i++)
{
for (int j = 0; j < n; j++)
{
if(matrix[i][j]==0)
{
a.add(i);
b.add(j);
}
}
}
//將所有行上值為0的那一行的值都改為0
for(int i:a)
{
for(int j=0;j
