本文注重从不同侧面反映数学思想在实际问题中的灵活应用，既注重算法原理的通俗性，也注重算法应用的实现性，克服了很多读者看懂算法却解决不了实际问题的困难-The selected cases are representative, focusing on different aspects reflecting the flexible application of mathematical thinking in practical problems, both focusing algorith