Submission #294862

#	Time	Username	Problem	Language	Result	Execution time	Memory
294862		shrek12357	Rice Hub (IOI11_ricehub)	C++14	100 / 100	89 ms	1536 KiB

ricehub

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <map>
#include <set>
#include <climits>
#include <cmath>
#include <fstream>
#include <queue>
#include "ricehub.h"
using namespace std;
 
bool tern(int lo, int hi, long long pre[], long long b, int s1, int s2) {
	if (hi - lo == 1) {
		long long val1 = pre[hi + 1] - pre[hi] - pre[lo + 1] + pre[lo];
		return val1 <= b;
	}
	while (hi >= lo) {
		int mid1 = lo + (hi - lo) / 3;
		int mid2 = hi - (hi - lo) / 3;
		long long val1 = pre[s2 + 1] - pre[mid1 + 1] - (s2- mid1)*(pre[mid1 + 1] - pre[mid1]) + (mid1 - s1)*(pre[mid1 + 1] - pre[mid1]) - pre[mid1] + pre[s1];
		long long val2 = pre[s2 + 1] - pre[mid2 + 1] - (s2 - mid2)*(pre[mid2 + 1] - pre[mid2]) + (mid2 - s1)*(pre[mid2 + 1] - pre[mid2]) - pre[mid2] + pre[s1];
		if (val1 <= b || val2 <= b) {
			return true;
		}
		if (val1 < val2) {
			hi = mid2 - 1;
		}
		else if (val1 > val2) {
			lo = mid1 + 1;
		}
		else {
			lo = mid1 + 1;
			hi = mid2 - 1;
		}
	}
	return false;
}
 
bool check(int r, int mid, long long pre[], long long b) {
	if (mid == 0) {
		return true;
	}
	for (int i = mid - 1; i < r; i++) {
		if (tern(i - (mid - 1), i, pre, b, i - (mid - 1), i)) {
			return true;
		}
	}
	return false;
}
 
int besthub(int r, int l, int x[], long long b) {
	int lo = 0;
	int hi = r;
	int best = 0;
	long long pre[r + 1];
  pre[0] = 0;
	for (int i = 0; i < r; i++) {
		pre[i + 1] = pre[i] + x[i];
	}
	while (hi >= lo) {
		int mid = (hi + lo) / 2;
		if (check(r, mid, pre, b)) {
			best = max(best, mid);
			lo = mid + 1;
		}
		else {
			hi = mid - 1;
		}
	}
	//cout << best << endl;
	return best;
}

• Subtask 1: 17 / 17
• Subtask 2: 25 / 25
• Subtask 3: 26 / 26
• Subtask 4: 32 / 32