【java】498. Diagonal Traverse

问题原文https://leetcode-cn.com/problems/diagonal-traverse/description/

 public int[] findDiagonalOrder(int[][] matrix) {
        int r = matrix.length;
        if(r == 0) return new int[0];
        int c = matrix[0].length;
        boolean direction = true;//表示方向向上
        int[] res = new int[r*c];
        int i = 0;
        int j = 0;
        int count = -1;
        while(i < r && j < c) {
        	res[++count] = matrix[i][j];
        	if(direction) {
        		int x = i-1;
        		int y = j+1;
        		if(x>=0&&y<c) {
        			i = x;
        			j = y;
        		}else {
        			if(y<c) {
        				j = y;
        			}else {
        				i+=1;
        			}
    				direction = !direction;
        		}
        	}else {
        		int x = i+1;
        		int y = j-1;
        		if(x<r&&y>=0) {
        			i = x;
        			j = y;
        		}else {
        			if(x<r) {
        				i = x;
        			}else {
        				j+=1;
        			}
    				direction = !direction;
        		}
        	}
        }
        return res;
    }