2020春季学期第八周学习总结

      本周学习了python编程的一些常见算法编程实现，总结如下：

1、蒙特·卡罗法计算圆周率

import random
print("掷飞镖次数:")
number = int(input())
k = 0
for i in range(1, number + 1):
    x = random.uniform(-1, 1)  # x随机取到-1到1的随机数
    y = random.uniform(-1, 1)  # Y随机取到-1到1的随机数
    if (x * x + y * y <= 1):
        k += 1
print("输出值为:")
print(k / number * 4)

运行结果：

2、模拟页面调度LRU算法

def LRU(Pages, Num, n):
    temp = []
    t= 0
    for p in lst:
        num = len(temp)
        if num < n:
            t += 1
            temp.append(p)
        elif num == n:  # 要访问的新页面已在主存块中
            if p in temp:  # 处理“主存块”，把最新访问的页面交换到列表尾部
                pos = temp.index(p)
                temp = temp[:pos] + temp[pos + 1:] + [p]
            else:  # 把最早访问的页面踢掉，调入新页面
                temp.pop(0)
                temp.append(p)
                t+= 1
    return t
n = int(input())
lst = tuple(input().split(" "))
print(LRU(lst, 3, n))

运行结果：

3、杨辉三角形

def yang(i, j):  # i为行，j为列
    if j == 0 or j == i:
        return 1
    else:
        return yang(i - 1, j) + yang(i - 1, j - 1)

a=int(input())
for i in range(0, a):
    print()
    for n in range(0, a - i):
        print(" ", end="")  # 控制每一行前面的空格
    for j in range(0, i + 1):
        print(yang(i, j), "", end="")

运行结果：

4、查找鞍点

list1=[]
list_max=[]
list_min=[]
for i in range(5):
    list=input().split()
    list_int=[int(x) for x in list]
    list1.append(list_int )
    k=0
    for j in list_int: 
        if j==max(list_int):
            break
        k=k+1
    list_max.append([i+1,k+1, max(list_int)])
#print(list_max)
list2=[[list1[j][i] for j in range(5)] for i  in range(5)]
i=0
for l in list2:
    i=i+1
    k = 0
    for j in l  :
        if j == min(l):
            break
        k = k + 1
    list_min.append([ k + 1,i, min(l)])
#print(list_min)

for i in list_max:
    for j in list_min:
        if str(i)==str(j):
            print(i,end=" ")

运行结果：

5、牛顿迭代法

def iteration(a, b, c, d, X):
    x = X
    if a == 0 and c ** 2 - 4 * b * d < 0:
        print("无解")
    elif a == 0 and b == 0 and c == 0 and d != 0:
        print("无解")
    elif a == 0 and b == 0 and c == 0 and d == 0:
        print("恒等")
    else:
        while abs(a * x * x * x + b * x * x + c * x + d) > 0.000001:
            x = x - (a * x * x * x + b * x * x + c * x + d) / (3 * a * x * x + 2 * b * x + c)
        print("x=%.2f" % x,end=" ")
a, b, c, d, x = input().split()
iteration(float(a), float(b), float(c), float(d), float(x))

运行结果：