输入一个矩阵,按照从外向里以顺时针的顺序依次打印出每一个数字,例如,如果输入如下4 X 4矩阵: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 则依次打印出数字1,2,3,4,8,12,16,15,14,13,9,5,6,7,11,10.
package offer.printMatrix;
import java.util.ArrayList;
public class Solution {
public ArrayList<Integer> printMatrix(int [][] matrix) {
ArrayList<Integer> rs=new ArrayList();
int row_len = matrix.length;
int col_len = matrix[0].length;
int min_len = Math.min(row_len,col_len);
if(row_len==1){
for(int i=0;i<col_len;i++){
rs.add(matrix[0][i]);
}
}else if(col_len==1){
for(int i=0;i<row_len;i++){
rs.add(matrix[i][0]);
}
}else{
for(int k=0;k<min_len/2;k++){
for(int i=k,j=k;j<col_len-k-1;j++){//第一条边,行不变,列 k->len-k-1
rs.add(matrix[i][j]);
}
for(int i=k,j=col_len-k-1;i<row_len-k-1;i++){//第二条边,列不变,行 k->len-k-1
rs.add(matrix[i][j]);
}
for(int i=row_len-k-1,j=col_len-k-1;j>k;j--){//第三条边,行不变,列 len-k-1 ->k
rs.add(matrix[i][j]);
}
for(int i=row_len-k-1,j=k;i>k;i--){//第四条边,列不变,行 len-k-1 -> k
rs.add(matrix[i][j]);
}
}
if(min_len%2==1){
if(row_len==col_len){
rs.add(matrix[row_len/2][row_len/2]);
}else{
for(int i=row_len/2;i<col_len-1;i++){
rs.add(matrix[row_len/2][i]);
}
}
}
}
return rs;
}
public static void main(String[] args){
Solution solution=new Solution();
int [][] matrix={{1,2,3,4,5},{6,7,8,9,10},{11,12,13,14,15}};
ArrayList<Integer> rs = solution.printMatrix(matrix);
for(int i=0;i<rs.size();i++){
System.out.print(rs.get(i)+" ");
}
}
}