제출 #428850

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
428850		shenxy	Sparklers (JOI17_sparklers)	C++11	100 / 100	40 ms	2884 KiB

sparklers

#include <cstdio>
#include <algorithm>
#include <cstring>
using namespace std;
int N, K;
long long T, X[100000], m;
bool check() {
	long long arr[N];
	for (int i = 0; i < N; ++i) arr[i] = 2 * m * T * i - X[i];
	int l = K - 1, r = K - 1, ml = min_element(arr, arr + K) - arr, mr = max_element(arr + K - 1, arr + N) - arr;
	long long rl = arr[K - 1], rr = arr[K - 1];
	while (l > ml || r < mr) {
		bool ch = false;
		while (l > ml && arr[l - 1] <= rr) rl = min(rl, arr[--l]), ch = true;
		while (r < mr && arr[r + 1] >= rl) rr = max(rr, arr[++r]), ch = true;
		if (!ch) return false;
	}
	l = 0, r = N - 1, rl = arr[0], rr = arr[N - 1];
	if (rl > rr) return false;
	while (l < ml || r > mr) {
		bool ch = false;
		while (l < ml && arr[l + 1] <= rr) rl = min(rl, arr[++l]), ch = true;
		while (r > mr && arr[r - 1] >= rl) rr = max(rr, arr[--r]), ch = true;
		if (!ch) return false;
	}
	return true;
}
int main() {
	scanf("%d %d %lld", &N, &K, &T);
	for (int i = 0; i < N; ++i) scanf("%lld", &X[i]);
	long long l = 0, u = 10000000000 / T;
	while (l != u) {
		m = (l + u) / 2;
		if (!check()) l = m + 1;
		else u = m;
	}
	printf("%lld", l);
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

sparklers.cpp: In function 'int main()':
sparklers.cpp:29:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |  scanf("%d %d %lld", &N, &K, &T);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
sparklers.cpp:30:35: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |  for (int i = 0; i < N; ++i) scanf("%lld", &X[i]);
      |                              ~~~~~^~~~~~~~~~~~~~~

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