Submission #161855

#	Time	Username	Problem	Language	Result	Execution time	Memory
161855		boolodifjenula	Lun (COCI19_lun)	Cpython 3	30 / 50	27 ms	3556 KiB

lun

N=int(input())
S=input()
T=S[N-1]
z=0
if T=="x":
    for i in range(N-2,-1,-1):
        if N%2==0 and i%2==0 or N%2==1 and i%2==1:
            z+=(2*int(S[i]))%10+(2*int(S[i]))//10
        else:
            z+=int(S[i])
    print(z*9%10)
else:
    m=0
    T=int(T)
    x=0
    for i in range(N-2,-1,-1):
        if S[i]!="x" and (N%2==0 and i%2==0 or N%2==1 and i%2==1):
            z+=(2*int(S[i]))%10+(2*int(S[i]))//10
        elif S[i]!="x":
            z+=int(S[i])
        if S[i]=="x":
            m=i
    if z%10<T:
        x=T-z%10
    elif z*9%10==T:
        x=0
    else:
        x=10+T-z%10
    if N%2==0 and m%2==0 and x!=1 or N%2==1 and m%2==1 and x!=1:
        x//=2
    print(x)

• Subtask 1: 30 / 50