对于一个矩阵,请设计一个算法,将元素按“之”字形打印。具体见样例。
给定一个整数矩阵mat,以及他的维数nxm,请返回一个数组,其中元素依次为打印的数字。
测试样例:
[[1,2,3],[4,5,6],[7,8,9],[10,11,12]],4,3
返回:[1,2,3,6,5,4,7,8,9,12,11,10]
import java.util.*;
public class Printer {
private static int index = 0;
public int[] printMatrix(int[][] mat, int n, int m) {
int[] res = new int[mat.length * mat[0].length];
int tR = 0;
int tC = 0;
int dR = mat.length - 1;
int dC = mat[0].length - 1;
boolean fromRight = false;
while (tR != dR+1) {
printLevel(mat, tC, dC, tR++, fromRight, res);
fromRight = !fromRight;
}
return res;
}
private static void printLevel(int[][] mat, int tC, int dC, int tR,
boolean fromUp, int[] res) {
if (fromUp) {
while (tC - 1 != dC) {
res[index++] = mat[tR][dC--];
}
} else {
while (tC != dC + 1) {
res[index++] = mat[tR][tC++];
}
}
}
}