Submission #3916352

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Source Code Expand

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define i_7 (ll)(1E9+7)
#define i_5 (ll)(1E9+5)
ll mod(ll a){
    ll c=a%i_7;
    if(c>=0)return c;
    else return c+i_7;
}
typedef pair<int,int> i_i;
typedef pair<ll,ll> l_l;
ll inf=(ll)1E12;
#define rep(i,l,r) for(ll i=l;i<=r;i++)
#define pb push_back
ll max(ll a,ll b){if(a<b)return b;else return a;}
ll min(ll a,ll b){if(a>b)return b;else return a;}
void Max(ll * pos,ll val){*pos=max(*pos,val);}//Max(&dp[i][j],dp[i-1][j]);
void Min(ll * pos,ll val){*pos=min(*pos,val);}
void Add(ll * pos,ll val){*pos=mod(*pos+val);}
const long double EPS=1E-8;
////////////////////////////////////////

ll f(ll n){
    ll res=0;
    while(n>=1){
        if(n%2==0){
            n/=2;
            res++;
        }else break;
    }
    return res;
}

int main(){
    ll n;cin>>n;
    ll a[n];rep(i,0,n-1)cin>>a[i];
    bool changed[n];memset(changed,false,sizeof(changed));
    ll p[n];
    rep(i,0,n-1){
        p[i]=f(a[i]);
    }
    ll ans=0;
    for(ll i=40;i>=0;i--){
        ll c=0;
        ll num=-1;
        rep(j,0,n-1){
            if(changed[j]==false&&(a[j]>>i)&1)c++;
            if(p[j]==i)num=j;
        }
        if((c+ans)%2==1){
            if(num==-1){
                cout<<-1;return 0;
            }
            ans++;
            changed[num]=true;
        }
    }
    cout<<ans<<endl;
    return 0;
}

Submission Info

Judge Result