Submission #979100

#TimeUsernameProblemLanguageResultExecution timeMemory
979100lftroqSecret (JOI14_secret)C++14
100 / 100
370 ms4692 KiB
#include<secret.h>

int pref[15][1005],n,mask[1005],a[1005];

void dnc(int l,int r,int level,int a[])
{
    if(l==r) return;
    int mid=(l+r)>>1;
    pref[level][mid]=a[mid];
    pref[level][mid+1]=a[mid+1];
    for(int i=mid+2;i<=r;i++) pref[level][i]=Secret(pref[level][i-1],a[i]);
    for(int i=mid-1;i>=l;i--) pref[level][i]=Secret(a[i],pref[level][i+1]);
    for(int i=mid+1;i<=r;i++) mask[i]|=(1<<level);
    dnc(l,mid,level+1,a);dnc(mid+1,r,level+1,a);
}

void Init(int N,int A[])
{
    n=N;for(int i=0;i<n;i++) a[i]=A[i];
    dnc(0,N-1,0,A);
}

int Query(int L,int R)
{
    if(L==R) return a[L];
    int k=__builtin_ctz(mask[L]^mask[R]);
    return Secret(pref[k][L],pref[k][R]);
}
#Verdict Execution timeMemoryGrader output
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