Submission #1000734

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Source Code Expand

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

typedef int _loop_int;
#define REP(i,n) for(_loop_int i=0;i<(_loop_int)(n);++i)
#define FOR(i,a,b) for(_loop_int i=(_loop_int)(a);i<(_loop_int)(b);++i)
#define FORR(i,a,b) for(_loop_int i=(_loop_int)(b)-1;i>=(_loop_int)(a);--i)

#define DEBUG(x) cout<<#x<<": "<<x<<endl
#define DEBUG_VEC(v) cout<<#v<<":";REP(i,v.size())cout<<" "<<v[i];cout<<endl
#define ALL(a) (a).begin(),(a).end()

#define CHMIN(a,b) a=min((a),(b))
#define CHMAX(a,b) a=max((a),(b))

// mod
const ll MOD = 1000000007ll;
#define FIX(a) ((a)%MOD+MOD)%MOD

// floating
typedef double Real;
const Real EPS = 1e-11;
#define EQ0(x) (abs(x)<EPS)
#define EQ(a,b) (abs(a-b)<EPS)
typedef complex<Real> P;

int n;
int a[125252];
int m;

int main(){
  scanf("%d",&n);
  REP(i,n)scanf("%d",a+i);
  int base = 1<<30;
  int ans = 0;
  REP(_,30){
    base>>=1;
    sort(a,a+n);
    m = 0;
    REP(i,n){
      if(i<n-2 && a[i]==a[i+1]){
        ++i;
      }else{
        a[m++] = a[i];
      }
    }
    n = m;

    int x = lower_bound(a,a+n,base)-a;
    if((n-x)%2==1){
      // should eat
      if(a[x]==base){
        // eat
        a[x]--;
        ans++;
        x++;
      }else{
        puts("-1");
        return 0;
      }
    }
    FOR(i,x,n)a[i]^=base;
  }
  printf("%d\n",ans);
  return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:39:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&n);
                 ^
./Main.cpp:40:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   REP(i,n)scanf("%d",a+i);
                          ^

Judge Result