Submission #27845

#	Time	Username	Problem	Language	Result	Execution time	Memory
27845		khsoo01	Sparklers (JOI17_sparklers)	C++11	0 / 100	0 ms	2800 KiB

sparklers

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const long double eps = 1e-9;
const ll N = 100005, inf = 1e9;
ll n, k, t, a[N];

bool can (ll P) {
	ll S = k, E = k, C = 0;
	for(ll i=1;i<n;i++) {
		if(a[S]-a[S-1] < a[E+1]-a[E]) {
			C += a[S]-a[S-1]; S--;
		}
		else {C += a[E+1]-a[E]; E++;}
		if(i*P*2+eps < (long double)C/t) return false;
	}
	return true;
}

int main()
{
	scanf("%lld%lld%lld",&n,&k,&t);
	bool f = false;
	for(ll i=1;i<=n;i++) {
		scanf("%lld",&a[i]);
		if(a[i] != a[i-1]) f = true;
	}
	if(!f) {puts("0"); return 0;}
	a[0] = -2*inf; a[n+1] = 2*inf;
	ll S = 1, E = inf;
	while(S<E) {
		ll M = (S+E)/2;
		can(M) ? E = M : S = M+1;
	}
	printf("%lld\n",S);
}

Compilation message (stderr)

sparklers.cpp: In function 'int main()':
sparklers.cpp:22:32: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld%lld%lld",&n,&k,&t);
                                ^
sparklers.cpp:25:22: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld",&a[i]);
                      ^

• Subtask 1: 0 / 30
• Subtask 2: 0 / 20
• Subtask 3: 0 / 50