Submission #217451

#	Time	Username	Problem	Language	Result	Execution time	Memory
217451		dimash241	Subway (info1cup19_subway)	C++17	93.06 / 100	15 ms	1272 KiB

subway

//#pragma GCC target("avx2")
//#pragma GCC optimize("O3")

//# include <x86intrin.h>
# include <bits/stdc++.h>

//# include <ext/pb_ds/assoc_container.hpp>
//# include <ext/pb_ds/tree_policy.hpp>

//using namespace __gnu_pbds;
using namespace std;
 
//template<typename T> using ordered_set = tree <T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

#define _USE_MATH_DEFINES_
#define ll long long
#define ld long double
#define Accepted 0
#define pb push_back
#define mp make_pair
#define sz(x) (int)(x.size())
#define every(x) x.begin(),x.end()
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define For(i,x,y)  for (ll i = x; i <= y; i ++) 
#define FOr(i,x,y)  for (ll i = x; i >= y; i --)
#define SpeedForce ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0)
// ROAD to...                                                                                                                                                                                                                Red

inline void Input_Output () {
	//freopen(".in", "r", stdin);
   //freopen(".out", "w", stdout);
}

const double eps = 0.000001;
const ld pi = acos(-1);
const int maxn = 1e7 + 9;
const int mod = 1e9 + 7;
const ll MOD = 1e18 + 9;
const ll INF = 1e18 + 123;
const int inf = 2e9 + 11;
const int mxn = 1e6 + 9;
const int N = 6e5 + 123;                                          
const int M = 22;
const int pri = 997;
const int Magic = 2101;

const int dx[] = {-1, 0, 1, 0};
const int dy[] = {0, -1, 0, 1};
 
int n, m, k;
vector < pair < int, int > > e;
int lst, ptr;


int main () {
	scanf("%d", &k);
	e.pb({0, -1});
	while(1) {
		lst = 0;
		int cur = 1;
		while(k >= cur) {
			k-=cur;
			e.pb({++ptr, lst});
			lst = ptr;
			++cur;
		}
		if (cur == 1) break;
	}
	printf("%d\n", sz(e));
	for (auto it : e) {
		printf("%d %d\n", it.first, it.second);
	}

	return Accepted;
}

// B...a

Compilation message (stderr)

subway.cpp: In function 'int main()':
subway.cpp:59:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &k);
  ~~~~~^~~~~~~~~~

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 43.0555555556 / 50