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Submission #67701

# Submission time Handle Problem Language Result Execution time Memory
67701 2018-08-15T08:53:09 Z tatatan XOR Sum (info1cup17_xorsum) C++11
45 / 100
 1600 ms 8216 KB 
#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define LL long long
#define st first
#define nd second
#define endl '\n'
using namespace std;

const int MAXN=1000005;
int n,a[MAXN],b[MAXN],ans;

int main() {

	scanf("%d",&n);
	for(int i=0;i<n;++i)
		scanf("%d",&a[i]);
	for(int i=0;i<30;++i) {
		int xo=(1<<(i+1))-1,t1,t2,t3;
		LL cnt=0;
		for(int j=0;j<n;++j) {
			b[j]=xo&a[j];
		}
		sort(b,b+n);
		t1=t2=t3=n;
		for(int j=0;j<n;++j) {
			while(t1&&b[t1-1]>=(1<<i)-b[j])
				--t1;
			while(t2&&b[t2-1]>=(1<<(i+1))-b[j])
				--t2;
			while(t3&&b[t3-1]>=(1<<(i+1))+(1<<i)-b[j])
				--t3;
			cnt+=(n-t1-(t3-t2));
		}
		for(int j=0;j<n;++j)
			if((b[j]*2)&(1<<i)) --cnt;
		cnt/=2;		
		for(int j=0;j<n;++j)
			if((b[j]*2)&(1<<i)) ++cnt;		
		if(cnt&1) ans+=(1<<i);
	}
	printf("%d\n",ans);

}

Compilation message

xorsum.cpp: In function 'int main()':
xorsum.cpp:16:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
xorsum.cpp:18:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&a[i]);
   ~~~~~^~~~~~~~~~~~

Subtask #1
7.0 / 7.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 376 KB Output is correct
2 Correct 12 ms 376 KB Output is correct

Subtask #2
0 / 11.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1666 ms 8216 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 1666 ms 8216 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #4
38.0 / 38.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 376 KB Output is correct
2 Correct 12 ms 376 KB Output is correct
3 Correct 296 ms 8216 KB Output is correct
4 Correct 290 ms 8216 KB Output is correct

Subtask #5
0 / 23.0

# Verdict Execution time Memory Grader output
1 Correct 15 ms 376 KB Output is correct
2 Correct 12 ms 376 KB Output is correct
3 Execution timed out 1666 ms 8216 KB Time limit exceeded
4 Halted 0 ms 0 KB -