Submission #667227

#	Time	Username	Problem	Language	Result	Execution time	Memory
667227		divad	Subway (info1cup19_subway)	C++14	100 / 100	7 ms	724 KiB

subway

#include <iostream>
#define int long long
using namespace std;
int k;

int gauss(int n){
    return n*(n+1)/2;
}

signed main()
{
    cin >> k;
    int ans = 0, st = 1, dr = 45000;
    /// 1 1 1 1 1 0 0 0 0 0 0
    ///         ^
    while(st <= dr){
        int mid = (st+dr)/2;
        if(gauss(mid) <= k){
            ans = mid;
            st = mid+1;
        }else{
            dr = mid-1;
        }
    }
    int rest = k-gauss(ans);
    int cnt = 1+ans+(rest > 0);
    cout << ans+1+(rest > 0) << "\n";
    cout << "0 -1\n";
    for(int i = 1; i <= ans; i++){
        cout << i << " " << i-1 << "\n";
    }
    if(rest){
        cout << ans+1 << " " << rest-1 << "\n";
    }
    return 0;
}

Compilation message (stderr)

subway.cpp: In function 'int main()':
subway.cpp:26:9: warning: unused variable 'cnt' [-Wunused-variable]
   26 |     int cnt = 1+ans+(rest > 0);
      |         ^~~

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