Submission #67197

#	Time	Username	Problem	Language	Result	Execution time	Memory
67197		zscoder	Wiring (IOI17_wiring)	C++17	0 / 100	6 ms	3752 KiB

wiring

#include "wiring.h"
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef vector<int> vi;
typedef pair<ll,ll> ii;

#define mp make_pair
#define pb push_back
#define fi first
#define se second

const int N = 100111;
const int M = 100111;
const int INF = int(1e9)+19;
ll dp[N+M+10][2];
int lastop[N+M+10]; //last opposite
ll S[N+M+10];
int nxtop[N+M+10];
ll sum(int l, int r)
{
	if(l==0) return S[r];
	else return S[r]-S[l-1];
}

long long min_total_length(std::vector<int> r, std::vector<int> b) 
{
	int n = r.size(); int m = b.size();
	r.pb(INF); b.pb(INF);
	vector<ii> vec;
	vec.pb(mp(-INF,-INF));
	int ptrr=0; int ptrb=0;
	for(int i=0;i<n+m;i++)
	{
		if(r[ptrr]<b[ptrb])
		{
			vec.pb(mp(r[ptrr],0));
			ptrr++;
		}
		else
		{
			vec.pb(mp(b[ptrb],1));
			ptrb++;
		}
	}
	lastop[0]=0;
	S[0]=0;
	for(int i=1;i<vec.size();i++) S[i]=vec[i].fi+S[i-1];
	for(int i=1;i<vec.size();i++) lastop[i]=(vec[i-1].se==vec[i].se?lastop[i-1]:i-1);
	nxtop[int(vec.size())-1]=INF;
	for(int i=int(vec.size())-2;i>=0;i--) nxtop[i]=(vec[i].se==vec[i+1].se?nxtop[i+1]:i+1);
	for(int i=0;i<N+M+10;i++){dp[i][0]=dp[i][1]=ll(1e18);}
	dp[0][0]=0; 
	for(int i=1;i<=n+m;i++)
	{
		ll pos=vec[i].fi; int ty=vec[i].se;
		for(int j=0;j<2;j++)
		{
			//spam opposite sides;
			if(!j)
			{
				ll d=0;
				for(int k=i-1;vec[k].se==(ty^1);k--)
				{
					d+=pos-vec[k].fi;
					dp[i][j] = min(dp[i][j], dp[k-1][0] + d);
				}
				int p = lastop[i];
				if(p>0)
				{
					ll d = sum(p+1,i)-ll(i-p)*vec[p].fi;
					//cerr<<i<<' '<<p<<' '<<d<<'\n';
					dp[i][j] = min(dp[i][j], dp[p-1][0] + d);
					if(i-p>=2&&vec[p-1].se==vec[p].se)
					{
						dp[i][j] = min(dp[i][j], dp[p-1][1] + d - (vec[p+1].fi - vec[p].fi));
					}
				}
			}
			if(j&&nxtop[i]<n+m) //connect to next
			{
				ll d = vec[nxtop[i]].fi-vec[i].fi;
				dp[i][j] = min(dp[i][j], dp[i-1][0] + d);
			}
			//cerr<<i<<' '<<j<<' '<<dp[i][j]<<'\n';
		}
	}
	return dp[n+m][0];
}

Compilation message (stderr)

wiring.cpp: In function 'long long int min_total_length(std::vector<int>, std::vector<int>)':
wiring.cpp:50:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1;i<vec.size();i++) S[i]=vec[i].fi+S[i-1];
              ~^~~~~~~~~~~
wiring.cpp:51:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=1;i<vec.size();i++) lastop[i]=(vec[i-1].se==vec[i].se?lastop[i-1]:i-1);
              ~^~~~~~~~~~~

• Subtask 1: 0 / 7
• Subtask 2: 0 / 13
• Subtask 3: 0 / 10
• Subtask 4: 0 / 25
• Subtask 5: 0 / 45