报告简介：
    In recent decades there has been a trend of increasing applications of the probabilistic method in combinatorics. To warm up we present a few classical results solved by the probabilistic model. Then we discuss a problem in somehow reverse direction, to show that combinatorial methodology may be used in probabilistic analysis.

报告人简介：
   宋春伟，北京大学数学科学学院教授。研究方向：组合数学与图论，特别是格路径计数理论与组合统计量、极值组合学、概率方法、图的重要参数与图结构。现任中国数学会理事、北京数学会理事、Math Reviews评论人。