CSES - Putka Open 2020 – 5/5 - Results
Submission details
Task:Pyramidi
Sender:tsiki2
Submission time:2020-11-29 22:56:25 +0200
Language:C++ (C++11)
Status:READY
Result:17
Feedback
groupverdictscore
#1ACCEPTED17
#20
Test results
testverdicttimegroup
#1ACCEPTED0.01 s1, 2details
#2ACCEPTED0.01 s1, 2details
#3ACCEPTED0.01 s1, 2details
#4ACCEPTED0.01 s1, 2details
#5ACCEPTED0.01 s1, 2details
#6ACCEPTED0.01 s1, 2details
#7ACCEPTED0.01 s1, 2details
#8ACCEPTED0.01 s1, 2details
#9ACCEPTED0.01 s1, 2details
#10ACCEPTED0.01 s1, 2details
#11ACCEPTED0.01 s1, 2details
#12ACCEPTED0.01 s1, 2details
#13ACCEPTED0.01 s1, 2details
#14ACCEPTED0.01 s1, 2details
#15ACCEPTED0.01 s1, 2details
#16--2details
#17--2details
#18--2details
#19--2details
#20--2details

Compiler report

input/code.cpp: In function 'int solve(std::vector<int>&)':
input/code.cpp:101:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i = 0; i < a.size(); i++) {
                  ~~^~~~~~~~~~
input/code.cpp:100:6: warning: unused variable 'nom_twos' [-Wunused-variable]
  int nom_twos = cum_twos[n];
      ^~~~~~~~

Code

#include <stdio.h> // include before iostream for faster scanf
#include <iostream>
#include <vector>
#include <string>
#include <map>
#include <unordered_map>
#include <algorithm>
#include <utility>
#include <set>
#include <unordered_set>
#include <cmath>
#include <math.h>
#include <queue>
#include <stdlib.h>
#include <string.h>
#include <sstream>
#include <tuple>
#include <utility>
#include <iomanip>
#include <iterator>

using namespace std;
typedef long long LL;

#define printv(printVec) for (auto printVecIter : (printVec)) cout << printVecIter << " "; cout << endl;

// g++ -Wall -Wshadow -std=c++11 a.cpp && ./a.out


vector<int> twos_per_num;
vector<int> cum_twos;

int twos(int n) {
	int ans = 0;
	while ((n%2) == 0 && n>1) {
		ans++;
		n/= 2;
	}
	return ans;
}




long long degree(long long a, long long k, long long p) {
  long long res = 1;
  long long cur = a;

  while (k) {
    if (k % 2) {
      res = (res * cur) % p;
    }
    k /= 2;
    cur = (cur * cur) % p;
  }
  return res;
}

LL get_degree(long long n, long long p) { // returns the degree with which p is in n!
  LL degree_num = 0;
  long long u = p;
  long long temp = n;

  while (u <= temp) {
    degree_num += temp / u;
    u *= p;
  }
  return degree_num;
}

long long combinations(LL n, LL k, long long p) {
  LL num_degree = get_degree(n, p) - get_degree(n - k, p);
  LL den_degree = get_degree(k, p);

  if (num_degree > den_degree) {
    return 0;
  }
  long long res = 1;
  for (long long i = n; i > n - k; --i) {
    long long ti = i;
    while(ti % p == 0) {
      ti /= p;
    }
    res = (res * ti) % p;
  }
  for (long long i = 1; i <= k; ++i) {
    long long ti = i;
    while(ti % p == 0) {
      ti /= p;
    }
    res = (res * degree(ti, p-2, p)) % p;
  }
  return res;
}


int solve(vector<int> & a) {
	int n = a.size() - 1;
	int ans = 0;
	int nom_twos = cum_twos[n];
	for (int i = 0; i < a.size(); i++) {
		if (combinations(n, i, 2) == 1) {
			ans ^= a[i];
		}
		// int d1 = i;
		// int d2 = a.size() - i - 1;
		// int dist = min(d1, d2);
		// int div = cum_twos[dist] + cum_twos[n-i];
		// if (nom_twos == div || dist == 0) {
		// 	// cout << a[i] << endl;
			
		// }
	}
	return ans;
}



int main() {
	std::ios::sync_with_stdio(false);cin.tie(0);
	int n;
	cin >> n;

	int cumsum = 0;
	for (int i = 0; i < 200000; i++) {
		int t = twos(i);
		twos_per_num.push_back(t);
		cumsum += t;
		cum_twos.push_back(cumsum);
	}

	// cout << "\n"<< cum_twos[2] << " xx " <<cum_twos[5]<<endl;

	vector<int> a(n);
	for (int i=0; i <n;i++) {
		cin>>a[i];
	}

	cout << solve(a) << endl;


}

Test details

Test 1

Group: 1, 2

Verdict: ACCEPTED

input
1
80

correct output
80

user output
80

Test 2

Group: 1, 2

Verdict: ACCEPTED

input
2
69 91

correct output
30

user output
30

Test 3

Group: 1, 2

Verdict: ACCEPTED

input
3
47 74 75

correct output
100

user output
100

Test 4

Group: 1, 2

Verdict: ACCEPTED

input
4
94 22 100 43

correct output
7

user output
7

Test 5

Group: 1, 2

Verdict: ACCEPTED

input
5
50 82 47 40 51

correct output
1

user output
1

Test 6

Group: 1, 2

Verdict: ACCEPTED

input
6
90 27 98 85 47 14

correct output
96

user output
96

Test 7

Group: 1, 2

Verdict: ACCEPTED

input
7
55 82 52 9 65 90 86

correct output
20

user output
20

Test 8

Group: 1, 2

Verdict: ACCEPTED

input
8
45 52 52 95 40 85 3 46

correct output
34

user output
34

Test 9

Group: 1, 2

Verdict: ACCEPTED

input
9
77 16 59 32 22 41 87 89 78

correct output
3

user output
3

Test 10

Group: 1, 2

Verdict: ACCEPTED

input
10
59 78 34 26 71 9 82 68 80 74

correct output
111

user output
111

Test 11

Group: 1, 2

Verdict: ACCEPTED

input
100
100 6 10 53 84 80 7 87 3 82 26...

correct output
91

user output
91

Test 12

Group: 1, 2

Verdict: ACCEPTED

input
100
25 18 62 51 79 55 71 33 21 29 ...

correct output
58

user output
58

Test 13

Group: 1, 2

Verdict: ACCEPTED

input
100
3 20 19 60 11 84 94 79 63 59 9...

correct output
124

user output
124

Test 14

Group: 1, 2

Verdict: ACCEPTED

input
100
99 86 42 2 97 78 8 12 98 7 98 ...

correct output
49

user output
49

Test 15

Group: 1, 2

Verdict: ACCEPTED

input
100
19 19 14 30 80 53 21 18 26 85 ...

correct output
42

user output
42

Test 16

Group: 2

Verdict:

input
200000
852837035 608724072 368935143 ...

correct output
680579671

user output
(empty)

Test 17

Group: 2

Verdict:

input
200000
255817977 550740070 115276527 ...

correct output
177586289

user output
(empty)

Test 18

Group: 2

Verdict:

input
200000
30889540 9467827 526159961 367...

correct output
439343644

user output
(empty)

Test 19

Group: 2

Verdict:

input
200000
421000302 598694653 199802169 ...

correct output
184880259

user output
(empty)

Test 20

Group: 2

Verdict:

input
200000
578873143 289492857 855880936 ...

correct output
937457144

user output
(empty)