下图的矩阵顺时针打印结果为:1, 2, 3, 4, 8, 12, 16, 15, 14, 13, 9, 5, 6, 7, 11, 10
import java.util.ArrayList;
public class Solution {
public ArrayList<Integer> printMatrix(int [][] matrix) {
ArrayList<Integer> rel = new ArrayList<>();
int r1 = 0, r2 = matrix.length - 1, c1 = 0, c2 = matrix[0].length - 1;
while(r1 <= r2 && c1 <= c2) {
for(int i = c1; i <= c2; i++)
rel.add(matrix[r1][i]);
for(int i = r1+1; i <= r2; i++)
rel.add(matrix[i][c2]);
if(r1 != r2)
for(int i = c2-1; i >= c1; i--)
rel.add(matrix[r2][i]);
if(c1 != c2)
for(int i = r2-1; i > r1; i--)
rel.add(matrix[i][c1]);
r1++; r2--; c1++; c2--;
}
return rel;
}
}