Submission #218344

#	Time	Username	Problem	Language	Result	Execution time	Memory
218344		Lawliet	Intergalactic ship (IZhO19_xorsum)	C++17	17 / 100	2095 ms	1536 KiB

xorsum

#include <bits/stdc++.h>

using namespace std;
typedef long long int lli;

const int MAXN = 1010;
const int MAXQ = 100010;
const int MOD = 1000000007;

int n, q;

int v[MAXN];
int L[MAXQ];
int R[MAXQ];
int X[MAXQ];
int aux[MAXQ];

void mod(lli& k) { if( k >= MOD ) k -= MOD; }

int main()
{
	scanf("%d",&n);

	for(int i = 1 ; i <= n ; i++)
		scanf("%d",&v[i]);

	scanf("%d",&q);

	for(int i = 0 ; i < q ; i++)
		scanf("%d %d %d",&L[i],&R[i],&X[i]);

	lli ans = 0;

	for(int mask = 0 ; mask < (1 << q) ; mask++)
	{
		for(int i = 1 ; i <= n ; i++)
			aux[i] = 0;

		for(int i = 0 ; i < q ; i++)
		{
			if( mask & (1 << i) )
			{
				aux[ L[i] ] ^= X[i];
				aux[ R[i] + 1 ] ^= X[i];
			}
		}

		int curXor = 0;

		lli sumAcc = 0;
		lli sumAll = 0;

		for(int i = 1 ; i <= n ; i++)
		{
			curXor ^= aux[i];
			int curV = v[i]^curXor;

			sumAll += 2*sumAcc*curV;
			sumAll %= MOD;

			sumAll += curV*curV*i;
			mod( sumAll );

			ans += sumAll;
			mod( ans );

			sumAcc += curV*i;
			mod( sumAcc );
		}
	}	

	printf("%lld\n",ans);
}

Compilation message (stderr)

xorsum.cpp: In function 'int main()':
xorsum.cpp:22:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
xorsum.cpp:25:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&v[i]);
   ~~~~~^~~~~~~~~~~~
xorsum.cpp:27:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&q);
  ~~~~~^~~~~~~~~
xorsum.cpp:30:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d %d",&L[i],&R[i],&X[i]);
   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 5 / 5
• Subtask 3: 0 / 6
• Subtask 4: 0 / 9
• Subtask 5: 8 / 8
• Subtask 6: 0 / 11
• Subtask 7: 0 / 19
• Subtask 8: 0 / 30
• Subtask 9: 0 / 8