Submission #807110

#	Time	Username	Problem	Language	Result	Execution time	Memory
807110		LIF	Finding Routers (IOI20_routers)	C++14	97.90 / 100	2 ms	340 KiB

routers

#include "routers.h"
#include<bits/stdc++.h>
using namespace std;
int pos[300005];
int minn[300005];
bool check(int now,int find)
{
	int idx = use_detector(now);
	minn[idx] = min(minn[idx],now);
	if(idx >= find)return true;
	else return false;
}
std::vector<int> find_routers(int l, int n, int q) {
    /*std::vector<int> ans;
    for (int i = 0; i < n; i++) {
		ans.push_back(0);
	}*/
	pos[0] = 0;
	for(int i=1;i<n;i++)minn[i] = l;
	for(int i=1;i<n;i++)
	{
		int ll = pos[i-1];
		int rr = minn[i];
		int ans;
		while(ll <= rr)
		{
			int mid = (ll+rr)>>1;
			if(check(mid,i) == true)
			{
				ans = mid;
				rr = mid - 1;
			}
			else ll = mid + 1;
		}
		pos[i] = pos[i-1] + (ans - 1 - pos[i-1]) * 2;
	}
	vector<int> temp;
	for(int i=0;i<n;i++)temp.push_back(pos[i]);
	return temp;
}

Compilation message (stderr)

routers.cpp: In function 'std::vector<int> find_routers(int, int, int)':
routers.cpp:35:28: warning: 'ans' may be used uninitialized in this function [-Wmaybe-uninitialized]
   35 |   pos[i] = pos[i-1] + (ans - 1 - pos[i-1]) * 2;
      |                        ~~~~^~~

• Subtask 1: 16 / 16
• Subtask 2: 21 / 21
• Subtask 3: 23 / 23
• Subtask 4: 37.8976 / 40