oj.uz

Submission #362480

# Submission time Handle Problem Language Result Execution time Memory
362480 2021-02-03T10:50:29 Z keta_tsimakuridze XOR Sum (info1cup17_xorsum) C++14
45 / 100
 1600 ms 42196 KB 
#include<bits/stdc++.h>
#define int long long
#define f first
#define s second
using namespace std;
const int N=1e6+5;
int a[N],s[N],n,cnt,c[2],ans,cur,pos[N];
vector< int  > v[2];
void Sort(int i){
	v[0].clear();
	v[1].clear();
	for(int k=1;k<=n;k++){
		int b = ((1ll<<i)&a[pos[k]]);
		b=min(b,1ll);
		v[b].push_back(pos[k]);
	}
	cur=0;
	for(int j=0;j<=1;j++){
		for(int k=0;k<v[j].size();k++){
			cur++;
			pos[cur]=v[j][k];
		}
	}
}
main(){
	ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0);
	cin>>n;
	for(int k=1;k<=n;k++){
		cin>>a[k]; pos[k]=k;
		cnt+=c[(a[k]&1)^1];
		c[a[k]&1]++;
		s[k]=a[k]&1;
	}
	if(cnt%2) ans=1;
	Sort(0);
	for(int i=1;i<=30;i++){
		Sort(i);
		for(int k=1;k<=n;k++)
		s[k]+=a[k]&(1ll<<i);
		cnt=0;
		int l=n,r=n,l1=n,r1=n;
		for(int k=1;k<=n;k++){
		         while(r && s[pos[r]] + s[pos[k]] >= (1ll<<(i+1)) ) r--;
		         while(l && s[pos[l]] + s[pos[k]] >= (1ll<<i) ) l--;
		         cnt += r-l;
		         while( l1&&s[pos[l1]] + s[pos[k]] >=((1ll<<(i+1))+(1ll<<i)) ) l1--;
		         cnt+=n-l1;
		}
		
		int c1=0;
		for(int k=1;k<=n;k++){
		           if((2*a[k])&(1ll<<i)) c1++;
		}

		if((c1+(cnt-c1)/2)%2==1) ans+=1ll<<i;
		
	}
	cout<<ans;
}

Compilation message

xorsum.cpp: In function 'void Sort(long long int)':
xorsum.cpp:19:16: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |   for(int k=0;k<v[j].size();k++){
      |               ~^~~~~~~~~~~~
xorsum.cpp: At global scope:
xorsum.cpp:25:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   25 | main(){
      |      ^
xorsum.cpp: In function 'int main()':
xorsum.cpp:41:20: warning: unused variable 'r1' [-Wunused-variable]
   41 |   int l=n,r=n,l1=n,r1=n;
      |                    ^~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 492 KB Output is correct
2 Correct 5 ms 492 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1670 ms 42196 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1670 ms 42196 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
38.0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 492 KB Output is correct
2 Correct 5 ms 492 KB Output is correct
3 Correct 141 ms 4964 KB Output is correct
4 Correct 137 ms 4836 KB Output is correct

Subtask #5
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 5 ms 492 KB Output is correct
2 Correct 5 ms 492 KB Output is correct
3 Execution timed out 1670 ms 42196 KB Time limit exceeded
4 Halted 0 ms 0 KB -