74. Search a 2D Matrix

https://leetcode-cn.com/problems/search-a-2d-matrix/

（图片来源https://leetcode-cn.com/problems/search-a-2d-matrix/

）

 public boolean searchMatrix(int[][] matrix, int target) {
        if(matrix == null || matrix.length < 1 || matrix[0].length < 1) {
            return false;
        }

        int r = matrix.length-1, c = 0;
        int re = matrix.length-1, ce = matrix[0].length-1;
        while(r >= 0 && c >= 0 && r <= re && c <= ce) {
            if(matrix[r][c] == target) {
                return true;
            }

            if(matrix[r][c] > target) {
                r --;
            } else {
                c ++;
            }
        }

        return false;
    }