Submission #119563

#	Time	Username	Problem	Language	Result	Execution time	Memory
119563		Charis02	Palembang Bridges (APIO15_bridge)	C++14	22 / 100	215 ms	16004 KiB

bridge

#include<iostream>
#include<stdio.h>
#include<vector>
#include<cmath>
#include<queue>
#include<utility>
#include<string.h>
#include<map>
#include<set>
#include<algorithm>
#define ll long long
#define pi pair < ll,ll >
#define mp(a,b) make_pair(a,b)
#define rep(i,a,b) for(int i = a;i < b;i++)
#define N 100004
#define INF 1e18

using namespace std;

ll n,k;
pi ar[N];
ll b,d;
char a,c;
ll ans,cnt;
vector <ll>possible;
vector < ll > ola;
set < ll > p;

ll abso(ll x)
{
    if(x<0)
        return -x;
    return x;
}

ll checkbridge(ll x,ll y)
{
    ll res = ans;

    rep(i,0,cnt)
    {
        if(ar[i].first <= x && x <= ar[i].second)
        {
            res += ar[i].second-ar[i].first;
        }
        else if(ar[i].first <= y && y <= ar[i].second)
        {
            res+=ar[i].second-ar[i].first;
        }
        else
        {
            res += 2*min(min(abso(ar[i].first-x),abso(ar[i].second-x)),min(abso(ar[i].first-y),abso(ar[i].second-y)))+(ar[i].second-ar[i].first);
        }
    }

 //   cout << x << " " << y << " " << res << endl;

    return res;
}

ll findans(ll x)
{
    ll low = 0;
    ll high = x;
    ll res = 0;

    while(low <= high)
    {
        ll mid = (low+high)/2;

        if(checkbridge(possible[x],possible[mid-1]) >= checkbridge(possible[x],possible[mid]))
        {
            low = mid+1;
            res = mid;
        }
        else
        {
            high = mid-1;
        }
    }
    return checkbridge(possible[x],possible[res]);
}

void solve2()
{
    ll fin = checkbridge(possible[0],possible[0]);

    ll low = 0;
    ll high = possible.size()-1;
    ll res = 0;

    while(low <= high)
    {
        ll mid = (low+high)/2;

        if(findans(mid-1) >= findans(mid))
        {
            low = mid+1;
            res = mid;
        }
        else
            high = mid-1;
    }

    fin = findans(res);
    low = 0;
    high = possible.size()-1;
    res = possible.size()-1;

    while(low <= high)
    {
        ll mid= (low+high)/2;

        if(mid==possible.size()-1||findans(mid+1) >= findans(mid))
        {
            high = mid-1;
            res=mid;
        }
        else
        {
            low=mid+1;
        }
    }

    cout << min(fin,findans(res)) << endl;
    return;
}

int main()
{
    ios_base::sync_with_stdio(false);

   // freopen("bridge_3_3.in","r",stdin);
    cin >> k >> n;

    rep(i,0,n)
    {
        cin >> a >> b >> c >> d;

        if(d < b)
            swap(b,d);

        if(a == c)
            ans += d-b;
        else
        {
            ar[cnt].first = b;
            ar[cnt].second = d;
            ola.push_back(b);
            ola.push_back(d);
            ans++;
            cnt++;
        }
    }

    if(cnt == 0)
    {
        cout << ans;
        return 0;
    }

    rep(i,0,cnt)
    {
        p.insert(ar[i].first);
        p.insert(ar[i].second);
    }

    for(set < ll >::iterator it = p.begin();it != p.end();it++)
    {
        possible.push_back(*it);
    }

    if(k == 2)
    {
        solve2();
        return 0;
    }

    ll low = 0;
    ll high = possible.size()-1;
    ll res = 0;

    while(low <= high)
    {
        ll mid = (low+high)/2;

        if(checkbridge(possible[mid-1],possible[mid-1]) >= checkbridge(possible[mid],possible[mid]))
        {
            low = mid+1;
            res = mid;
        }
        else
        {
            high = mid-1;
        }
    }

    cout << checkbridge(possible[res],possible[res]);

    return 0;
}

/*
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7

2 3
A 1 B 1
A 4 B 7
A 10 B 12
*/

Compilation message (stderr)

bridge.cpp: In function 'void solve2()':
bridge.cpp:114:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(mid==possible.size()-1||findans(mid+1) >= findans(mid))
            ~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 14 / 14
• Subtask 3: 0 / 9
• Subtask 4: 0 / 32
• Subtask 5: 0 / 37