#SHORTEST JOB FIRST(SJF)(CPU SCHEDULING)4
bt = [int(input(f"BurstTime for process {i}: ")) for i in range(int(input("No. of processes: ")))]
bt.sort()
wt = [sum(bt[:i]) for i in range(len(bt))]
tt = [bt[i] + wt[i] for i in range(len(bt))]
print(f"WaitingTime: {wt}\n")
print(f"TurnaroundTime: {tt}\n")
print(f"AverageWaitingTime: {sum(wt)/len(wt)}\n")
print(f"AverageTurnaroundTime: {sum(tt)/len(tt)}\n")

#BANKERS ALGORITHM(6)
def bankers(np, nr, avail, Max, allo):
    need = [[Max[i][j] - allo[i][j] for j in range(nr)] for i in range(np)]
    safe = []
    work = avail.copy()
    finish = [0] * np
    while len(safe) < np:
        found = False
        for i in range(np):
            if finish[i] == 0 and all(need[i][j] <= work[j] for j in range(nr)):
                work = [work[j] + allo[i][j] for j in range(nr)]
                safe.append(i)
                finish[i] = 1
                found = True
                break
        if not found:
            print("System is not in safe state")
            return False
    print("System in safe state.")
    print("Safe sequence is: ", end="")
    print(*[f"P{p}" for p in safe], sep=" -> ")
    return True
np = 5
nr = 3
avail = [3, 3, 2]
Max = [[7, 5, 3], [3, 2, 2], [9, 0, 2], [2, 2, 2], [4, 3, 3]]
allo = [[0, 1, 0], [2, 0, 0], [3, 0, 2], [2, 1, 1], [0, 0, 2]]
bankers(np, nr, avail, Max, allo)

#FIRST-FIT AND BEST-FIT (Contiguous Memory Allocation)7
def first_fit(bS,pS):
    for x in pS:
        for y in bS:
            if x<y:
                print(f"{x} --> {y}")
                bS.remove(y)
                break
        else:
            print(f"{x} --> cannot be placed")
def best_fit(bS,pS):
    new_pro = sorted(pS,reverse=True)
    new_blo = sorted(bS,reverse=True)
    first_fit(new_blo,new_pro)
bS= [100, 500, 200, 300, 600]
Bno= [1, 2, 3, 4, 5]
pS= [212, 417, 112, 426]
best_fit(bS,pS)

#FIRST IN FIRST OUT(FIFO)(PAGE REPLACEMENT ALGORITHM)8
def fifo():
    m, s, h = [], 3, 0
    for x in [7,0,1,2,0,3,0,4,2,3,0,3,2,3]:
        if len(m) < s: m.append(x)
        elif x in m: h += 1
        else: m[m.pop(0) and 0] = x
    print(f"hits: {h}\nmisses: {len(m)}")

fifo()

#LEAST RECENTLY USED(LRU)(PAGE REPLACEMENT ALGORITHM)8
from collections import deque
def lru(pages, ps):
    ph = deque(maxlen=page_size)
    for x in pages:
        if x not in ph:
            if len(ph) == ps:
                ph.popleft()
            ph.append(x)
            print("miss", ph)
        else:
            ph.remove(x)
            ph.append(x)
            print("hit", ph)
lru([7, 0, 1, 2, 0, 3, 0, 4, 2, 3, 0, 3, 2], 4)

#SHORTEST SEEK TIME FIRST(SSTF)(DISK SCHEDULING)10
def sstf():
    cur = int(input("position of the disk head: "))
    req = list(map(int, input("list of requests: ").split()))
    time = 0
    while req:
        closest = min(req, key=lambda x: abs(x - cur))
        time += abs(closest - cur)
    return move
        cur = closest
        req.remove(closest)
    print("Total seek time:", time)
sstf()

#FIRST COME FIRST SERVE(FCFS)(CPU SCHEDULING)10
def fcfs(req, head):
    move = abs(req[0] - head)
    for i in range(1, len(req)):
        move += abs(req[i] - req[i-1])
    return move
head = int(input("position of disk head: "))
req = list(map(int, input("disk requests: ").split()))
if not req:
    print("Error")
else:
    mov = fcfs(req, head)
    print("Total movements:", mov)