cf#320 Div.2 Problem D "Or" Game

#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
#define LL long long
int n,k,x;
int a[200005],l[200005],r[200005];
int main(){
    scanf("%d%d%d",&n,&k,&x);
    for(int i=1;i<=n;i++)
        scanf("%d",&a[i]);
    l[0]=0;
    for(int i=1;i<=n;i++)
        l[i]=(l[i-1]|a[i]);
    r[n+1]=0;
    for(int i=n;i>=1;i--)
        r[i]=(r[i+1]|a[i]);
    LL ans=0,A=1;
    for(int i=1;i<=k;i++)
        A*=x;
    for(int i=1;i<=n;i++)
        ans=max(ans,(A*a[i])|l[i-1]|r[i+1]);
    printf("%I64d\n",ans);//如果用%lld在CF上是不允许提交的
    return 0;
}