import numpy as np
import matplotlib.pyplot as plt 

x = np.linspace(0, 10, 20, 30)
print (x)
y = np.sin(x)

plt.plot(x, y, c="blue", ls="--", lw=1, alpha=0.5)
plt.scatter(x, y, c="red", marker="+")
plt.show()

#Q3
def syracuse(n):
    if n%2 == 0:
        return(n/2)
    else: 
        return(3*n+1)

Nmax = 100
x = np.linspace(0, Nmax, Nmax+1)
y = np.zeros(np.shape(x))
print(x)

u = int(input("Quelle est la valeur de u0 ?"))
y[0] = u 
for i in range(1,Nmax+1):
    y[i] = syracuse(u)
print(y)

plt.scatter(x,y)
plt.show()