递归结束条件：
递归算法必须有个基本结束条件递归算法必须改变自己的状态并向基本结束条件演进递归算法必须递归地调用自身 def fibo(n): if n<=1: #结束条件 return n return fibo(n-1)+fibo(n-2) #调用自己 print(fibo(8)) def to_str(n, base): convert_string = "0123456789ABCDEF" if n < base: return convert_string[n] else: return to_str(n//base, base) + convert_string[n % base] print(to_str(1453,5)) #动态规划 def recMC(coinValueList,change): minCoins = change if change in coinValueList: return 1 else: for i in [c for c in coinValueList if c <= change]: numCoins = 1 + recMC(coinValueList,change-i) if numCoins < minCoins: minCoins = numCoins return minCoins print(recMC([1,5,10,25],63))选择排序算法
def selectionSort(alist): for fillslot in range(len(alist)-1,0,-1): positionOfMax=0 for location in range(1,fillslot+1): if alist[location]>alist[positionOfMax]: positionOfMax = location temp = alist[fillslot] alist[fillslot] = alist[positionOfMax] alist[positionOfMax] = temp return alist alist = [54,26,93,17,77,31,44,55,20] print(alist) print(selectionSort(alist))冒泡排序
def bubbleSort(alist): for passnum in range(len(alist)-1,0,-1): for i in range(passnum): if alist[i]>alist[i+1]: temp = alist[i] alist[i] = alist[i+1] alist[i+1] = temp alist = [54,26,99,17,77,31,44,55,20] bubbleSort(alist) print(alist)插入排序
def insertionSort(alist): for index in range(1,len(alist)): currentvalue = alist[index] position = index while position>0 and alist[position-1]>currentvalue: alist[position]=alist[position-1] position = position-1 alist[position]=currentvalue return alist alist = [54,26,93,17,77,31,44,55,20] print(insertionSort(alist))