제출 #522593

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
522593		Be_dos	홀-짝 수열 (IZhO11_oddeven)	C++17	0 / 100	614 ms	296 KiB

oddeven

#include <iostream>
#include <cmath>
#include <cctype>
#include <vector>
#include <algorithm>
#include <set>
#include <map>
#include <deque>
#include <stack>
#include <unordered_set>
#include <sstream>
#include <cstring>
#include <iomanip>
#include <queue>
#include <unordered_map>
#include <random>
#include <cfloat>
#include <chrono>
#include <bitset>
#include <complex>
#include <immintrin.h>
#include <cassert>

int64_t int_sqrt(int64_t n) {
    int64_t res = 0;
    for(int64_t i = 1; i * i < n; i++)
        res = i;
    return res + 1;
}

int main() {
    int64_t n;
    std::cin >> n;

    int64_t block = (int_sqrt(1 + 8 * n)) / 2;
    int64_t block_end = block * (block + 1) / 2;
    int64_t block_start = block_end - block + 1;
    std::cout << block_start + (block - 1) * (block - 2) / 2 + (n - block_start) * 2;
    return 0;
}

//0  0        1           3                 6                 10
//1,  2, 4,   5, 7, 9,    10, 12, 14, 16,   17 19 21 23 25    26
//1   2  3    4  5  6     7   8    9  10    11 12 13 14 15    16

• Subtask 1: 0 / 100