6.Banker's Algorithm.py

# Program to Implement Bankers Algorithms
# Rohit Kumar | 1900320100131
def calNeed(max, allocation):
    need = []
    for i in range(5):
        l = []
        for j in range(3):
            l.append(max[i][j]-allocation[i][j])
        need.append(l)
    return need


def safe_seq(availabe, max, allocatin, need):
    n = len(allocatin)
    work = availabe.copy()
    finish = [False]*n
    ans = []
    k = 0
    while k < len(allocatin):
        for i in range(len(allocatin)):
            if finish[i] == False:
                if need[i][0] <= work[0] and need[i][1] <= work[1] and need[i][2] <= work[2]:
                    ans.append(f"P{i}")
                    for j in range(3):
                        allocatin[i][j] += need[i][j]
                        work[j] -= need[i][j]
                        need[i][j] = max[i][j]-allocatin[i][j]
                    for j in range(3):
                        work[j] += allocatin[i][j]
                    finish[i] = True
        k += 1
    return ans


if __name__ == "__main__":
    availabe = [3, 3, 2]
    max = [[7, 5, 3], [3, 2, 2], [9, 0, 2], [2, 2, 2], [4, 3, 3]]
    allocation = [[0, 1, 0], [2, 0, 0], [3, 0, 2], [2, 1, 1], [0, 0, 2]]
    need = calNeed(max, allocation)
    safeSeq=[]
    print("SAFE SEQUENCE", *safe_seq(availabe, max, allocation, need))

    while True:
        p = int(input("ENTER PROCESS ID  :: "))
        req = list(map(int, input("ENTER REQUEST  :: ").split()))
        flag = False
        if req[0] <= need[p][0] and req[1] <= need[p][1] and req[2] <= need[p][2]:  # step 1
            if req[0] <= availabe[0] and req[1] <= availabe[1] and req[2] <= availabe[2]:  # step 2
                for i in range(len(req)):
                    availabe[i] -= req[i]

                    allocation[p][i] += req[i]
                    need[p][i] -= req[i]
                safeSeq = safe_seq(availabe, max, allocation, need)
                flag = True
        if len(safeSeq) == 5:
            print("SAFE SEQUENCE ", *safeSeq)
        else:
            for i in range(len(req)):
                availabe[i] += req[i]
                allocation[p][i] -= req[i]
                need[p][i] += req[i]
        if flag == False:
            print("SAFE SEQUENCE NOT OBTAINED")
            
        con = input("WANT TO CONTINUE TYPE Y/N")
        if con == "n" or con == "N":
            break