Program 1
# Friend Recommendation System in Social Media using graphs
# System that recommends new friends to users in a
# social network by analyzing their mutual friends
# Features
# 1. Add new user
# 2. Create Friendship
# 3. Display Friendship on Social Network
# 4. Friend Recommendation
class FriendRecommendationSystem:
def __init__(self):
self.max_users = 20
self.users = []
self.graph = [[0 for _ in range(self.max_users)] for _ in range(self.max_users)]
def add_user(self, name):
if len(self.users) >= self.max_users:
print(" Maximum user limit reached.")
return
if name in self.users:
print(" User already exists.")
return
self.users.append(name)
print(f" User added: {name}")
def find_index(self, name):
try:
return self.users.index(name)
except ValueError:
return -1
def add_friendship(self, name1, name2):
i = self.find_index(name1)
j = self.find_index(name2)
if i == -1 or j == -1:
print(" One or both users not found.")
return
self.graph[i][j] = 1
self.graph[j][i] = 1
print(f" Friendship added between {name1} and {name2}")
def show_friends(self):
print("\n-------- Friend Lists ----------")
for i in range(len(self.users)):
print(f"{self.users[i]} -> ", end='')
for j in range(len(self.users)):
if self.graph[i][j] == 1:
print(self.users[j], end=' ')
print()
def recommend_friends(self, name):
idx = self.find_index(name)
if idx == -1:
print(" User not found.")
return
recommended = [0] * self.max_users
for i in range(len(self.users)):
if self.graph[idx][i] == 1:
for j in range(len(self.users)):
if self.graph[i][j] == 1 and j != idx and self.graph[idx][j] == 0:
recommended[j] += 1
print(f"\n Friend Recommendations for {name}:")
found = False
for i in range(len(self.users)):
if recommended[i] > 0:
print(f" - {self.users[i]} (Mutual Friends: {recommended[i]})")
found = True
if not found:
print("No recommendations at this time.")
def menu(self):
while True:
print("\n-----------Friend Recommendation System ---------------")
print("1. Add User")
print("2. Add Friendship")
print("3. Show Friends")
print("4. Recommend Friends")
print("5. Exit")
print("-------------------------------------------------------")
choice = input("Enter Your Choice: ")
if choice == '1':
name = input("Enter user name: ")
self.add_user(name)
elif choice == '2':
name1 = input("Enter first user name: ")
name2 = input("Enter second user name: ")
self.add_friendship(name1, name2)
elif choice == '3':
self.show_friends()
elif choice == '4':
name = input("Enter your name: ")
self.recommend_friends(name)
elif choice == '5':
print("Exiting...")
break
else:
print(" Invalid choice. Try again.")
# Run the program
if __name__ == "__main__":
system = FriendRecommendationSystem()
system.menu()
