CSES - Putka Open 2020 – 5/5

CSES - Putka Open 2020 – 5/5 - Results

Submission details
Task:	Pyramidi
Sender:	tsiki2
Submission time:	2020-11-29 23:03:49 +0200
Language:	C++11
Status:	READY
Result:	100

Feedback
group	verdict	score
#1	ACCEPTED	17
#2	ACCEPTED	83

Test results
test	verdict	time	group
#1	ACCEPTED	0.01 s	1, 2	details
#2	ACCEPTED	0.01 s	1, 2	details
#3	ACCEPTED	0.01 s	1, 2	details
#4	ACCEPTED	0.01 s	1, 2	details
#5	ACCEPTED	0.01 s	1, 2	details
#6	ACCEPTED	0.01 s	1, 2	details
#7	ACCEPTED	0.01 s	1, 2	details
#8	ACCEPTED	0.01 s	1, 2	details
#9	ACCEPTED	0.01 s	1, 2	details
#10	ACCEPTED	0.01 s	1, 2	details
#11	ACCEPTED	0.01 s	1, 2	details
#12	ACCEPTED	0.01 s	1, 2	details
#13	ACCEPTED	0.01 s	1, 2	details
#14	ACCEPTED	0.01 s	1, 2	details
#15	ACCEPTED	0.01 s	1, 2	details
#16	ACCEPTED	0.04 s	2	details
#17	ACCEPTED	0.04 s	2	details
#18	ACCEPTED	0.04 s	2	details
#19	ACCEPTED	0.04 s	2	details
#20	ACCEPTED	0.04 s	2	details

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++) {
                  ~~^~~~~~~~~~

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-dist];
		if (nom_twos == div || dist == 0) {
			ans ^= a[i];
			
		}
	}
	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` view save

correct output
`80` view save

user output
`80` view save

Test 2

Group: 1, 2

Verdict: ACCEPTED

input
`2 69 91` view save

correct output
`30` view save

user output
`30` view save

Test 3

Group: 1, 2

Verdict: ACCEPTED

input
`3 47 74 75` view save

correct output
`100` view save

user output
`100` view save

Test 4

Group: 1, 2

Verdict: ACCEPTED

input
`4 94 22 100 43` view save

correct output
`7` view save

user output
`7` view save

Test 5

Group: 1, 2

Verdict: ACCEPTED

input
`5 50 82 47 40 51` view save

correct output
`1` view save

user output
`1` view save

Test 6

Group: 1, 2

Verdict: ACCEPTED

input
`6 90 27 98 85 47 14` view save

correct output
`96` view save

user output
`96` view save

Test 7

Group: 1, 2

Verdict: ACCEPTED

input
`7 55 82 52 9 65 90 86` view save

correct output
`20` view save

user output
`20` view save

Test 8

Group: 1, 2

Verdict: ACCEPTED

input
`8 45 52 52 95 40 85 3 46` view save

correct output
`34` view save

user output
`34` view save

Test 9

Group: 1, 2

Verdict: ACCEPTED

input
`9 77 16 59 32 22 41 87 89 78` view save

correct output
`3` view save

user output
`3` view save

Test 10

Group: 1, 2

Verdict: ACCEPTED

input
`10 59 78 34 26 71 9 82 68 80 74` view save

correct output
`111` view save

user output
`111` view save

Test 11

Group: 1, 2

Verdict: ACCEPTED

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

correct output
`91` view save

user output
`91` view save

Test 12

Group: 1, 2

Verdict: ACCEPTED

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

correct output
`58` view save

user output
`58` view save

Test 13

Group: 1, 2

Verdict: ACCEPTED

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

correct output
`124` view save

user output
`124` view save

Test 14

Group: 1, 2

Verdict: ACCEPTED

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

correct output
`49` view save

user output
`49` view save

Test 15

Group: 1, 2

Verdict: ACCEPTED

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

correct output
`42` view save

user output
`42` view save

Test 16

Group: 2

Verdict: ACCEPTED

input
`200000 852837035 608724072 368935143 ...` view save

correct output
`680579671` view save

user output
`680579671` view save

Test 17

Group: 2

Verdict: ACCEPTED

input
`200000 255817977 550740070 115276527 ...` view save

correct output
`177586289` view save

user output
`177586289` view save

Test 18

Group: 2

Verdict: ACCEPTED

input
`200000 30889540 9467827 526159961 367...` view save

correct output
`439343644` view save

user output
`439343644` view save

Test 19

Group: 2

Verdict: ACCEPTED

input
`200000 421000302 598694653 199802169 ...` view save

correct output
`184880259` view save

user output
`184880259` view save

Test 20

Group: 2

Verdict: ACCEPTED

input
`200000 578873143 289492857 855880936 ...` view save

correct output
`937457144` view save

user output
`937457144` view save

Putka Open 2020 – 5/5

Pyramidi

Compiler report

Code

Test details

Test 1

Test 2

Test 3

Test 4

Test 5

Test 6

Test 7

Test 8

Test 9

Test 10

Test 11

Test 12

Test 13

Test 14

Test 15

Test 16

Test 17

Test 18

Test 19

Test 20

Tasks

Submissions (tsiki2)