Submission #585792

#	Time	Username	Problem	Language	Result	Execution time	Memory
585792		messiuuuuu	Palembang Bridges (APIO15_bridge)	C++14	78 / 100	162 ms	10256 KiB

bridge

#include<bits/stdc++.h>
#define task "C"
#define ll long long
#define ld long double
#define fi first
#define se second
#define pb push_back
using namespace std;
const int MAXN = 1e5 + 5;
const ll INF = 1e18 + 5;

int n, k;
struct TRoad
{
    char h, o;
    ll ph, po;
}a[MAXN];

ll more = 0;

void Input()
{
    cin >> k >> n;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i].h >> a[i].ph >> a[i].o >> a[i].po;
    }
    vector<int> cs;
    for (int i = 1; i <= n; i++)
    {
        if (a[i].h == a[i].o)
        {
            more += abs(a[i].ph - a[i].po);
        } else
        {
            cs.pb(i);
        }
    }

    for (int i = 0; i < cs.size(); i++)
    {
        a[i + 1] = a[cs[i]];
    }
    n = cs.size();
}

int truoc[MAXN];
vector<ll> num;
int dif;

void NenSo()
{
    for (int i = 1; i <= n; i++)
    {
        num.pb(a[i].ph);
        num.pb(a[i].po);
    }
    sort(num.begin(), num.end());
    num.erase(unique(num.begin(), num.end()), num.end());
    for (int i = 1; i <= n; i++)
    {
        a[i].ph = lower_bound(num.begin(), num.end(), a[i].ph) - num.begin() + 1;
        a[i].po = lower_bound(num.begin(), num.end(), a[i].po) - num.begin() + 1;
    }
    dif = num.size();
}

struct BIT
{
    vector<ll> fe;
    int sz;

    void Init(int _sz)
    {
        sz = _sz;
        fe.clear();
        fe.resize(sz + 1);
    }

    void add(int p, ll val)
    {
        for (; p <= sz; p += p & -p)
        {
            fe[p] += val;
        }
    }

    ll get(int r)
    {
        ll res = 0;
        for (; r; r -= r & -r)
        {
            res += fe[r];
        }
        return res;
    }

    ll get(int l, int r)
    {
        return get(r) - get(l - 1);
    }
};

ll prefsum[MAXN];

void Solve()
{
    vector<int> cs(n);
    iota(cs.begin(), cs.end(), 1);
    sort(cs.begin(), cs.end(), [](int i, int j)
         {
             return a[i].po + a[i].ph < a[j].po + a[j].ph;
         });
    NenSo();

    ll res = (n == 1 ? abs(num[a[1].po - 1] - num[a[1].ph - 1]) + 1 : INF);
    if (n == 0)
        res = 0;
    BIT bit[2];
    bit[0].Init(dif);
    bit[1].Init(dif);
    for (int i = 0; i + 1 < cs.size(); i++)
    {
        int p = cs[i];
        //cout << num[a[p].ph - 1] << ' ' << num[a[p].po - 1] << '\n';
        bit[0].add(a[p].po, 1);
        bit[0].add(a[p].ph, 1);
        bit[1].add(a[p].po, num[a[p].po - 1]);
        bit[1].add(a[p].ph, num[a[p].ph - 1]);
        int l = 1, r = dif;
        while (l <= r)
        {
            int mid = (l + r) / 2;
            if (bit[0].get(1, mid) >= i + 1)
                r = mid - 1;
            else
                l = mid + 1;
        }
        prefsum[i] = -bit[1].get(1, l) + num[l - 1] * bit[0].get(1, l)
                      + bit[1].get(l, dif) - num[l - 1] * bit[0].get(l, dif) + i + 1;
        //cout << prefsum[i] << '\n';
    }

    bit[0].Init(dif);
    bit[1].Init(dif);
    for (int i = (int)cs.size() - 1; i >= 1; i--)
    {
        int p = cs[i];
        bit[0].add(a[p].po, 1);
        bit[0].add(a[p].ph, 1);
        bit[1].add(a[p].po, num[a[p].po - 1]);
        bit[1].add(a[p].ph, num[a[p].ph - 1]);
        int l = 1, r = dif;
        while (l <= r)
        {
            int mid = (l + r) / 2;
            if (bit[0].get(1, mid) >= (int)cs.size() - i)
                r = mid - 1;
            else
                l = mid + 1;
        }
        res = min(res, prefsum[i - 1] + -bit[1].get(1, l) + num[l - 1] * bit[0].get(1, l)
                                        + bit[1].get(l, dif) - num[l - 1] * bit[0].get(l, dif) + (int)cs.size() - i);
    }
    //cout << more << '\n';
    cout << res + more;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
    if (fopen(task".INP","r"))
    {
        freopen(task".INP","r",stdin);
        freopen(task".OUT","w",stdout);
    }
    Input();
    Solve();
}

Compilation message (stderr)

bridge.cpp: In function 'void Input()':
bridge.cpp:40:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |     for (int i = 0; i < cs.size(); i++)
      |                     ~~^~~~~~~~~~~
bridge.cpp: In function 'void Solve()':
bridge.cpp:122:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  122 |     for (int i = 0; i + 1 < cs.size(); i++)
      |                     ~~~~~~^~~~~~~~~~~
bridge.cpp: In function 'int main()':
bridge.cpp:175:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  175 |         freopen(task".INP","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
bridge.cpp:176:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  176 |         freopen(task".OUT","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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