제출 #30581

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
30581		RayaBurong25_1	Roller Coaster Railroad (IOI16_railroad)	C++14	100 / 100	939 ms	47984 KiB

railroad

#include "railroad.h"
#include <set>
#include <algorithm>
#define INF 1000000007
std::set<long long> I;
std::vector<long long> Ic;
long long Fen[400005];
int Pa[400005];
int n;
typedef struct node node;
struct node
{
    int u, v;
    long long w;
};
int compareW(node a, node b)
{
    return (a.w < b.w);
}
std::vector<node> E;
void update(int pos, int val)
{
    for (; pos <= Ic.size(); pos += pos&-pos)
        Fen[pos] += val;
}
long long query(int pos)
{
    long long r = 0;
    for (; pos > 0; pos -= pos&-pos)
        r += Fen[pos];
    return r;
}
int uf(int u)
{
    return (Pa[u] == 0)?u:(Pa[u] = uf(Pa[u]));
}
void join(int u, int v)
{
    // printf("Join %d (%d) %d (%d)\n", u, Ic[u - 1], v, Ic[v - 1]);
    int pu = uf(u);
    int pv = uf(v);
    if (pu != pv)
        Pa[pu] = pv;
}
long long plan_roller_coaster(std::vector<int> s, std::vector<int> t) {
    n = (int) s.size();
    int i;
    I.insert(1);
    I.insert(INF);
    for (i = 0; i < n; i++)
    {
        I.insert(s[i]);
        I.insert(t[i]);
    }
    std::set<long long>::iterator it;
    for (it = I.begin(); it != I.end(); it++)
        Ic.push_back(*it);
    int u, v;
    for (i = 0; i < n; i++)
    {
        u = std::lower_bound(Ic.begin(), Ic.end(), s[i]) - Ic.begin() + 1;
        v = std::lower_bound(Ic.begin(), Ic.end(), t[i]) - Ic.begin() + 1;
        update(u, 1);
        update(v, -1);
        join(u, v);
    }
    update(Ic.size(), 1);
    update(1, -1);
    join(Ic.size(), 1);
    long long r, Ans = 0;
    for (i = 1; i < Ic.size(); i++)
    {
        r = query(i);
        // printf("r%d\n", r);
        if (r > 0)
        {
            Ans += r*(Ic[i] - Ic[i - 1]);
        }
        if (r != 0)
        {
            join(i, i + 1);
        }
        E.push_back({i, i + 1, (Ic[i] - Ic[i - 1])});
    }
    std::sort(E.begin(), E.end(), compareW);
    int pu, pv;
    for (i = 0; i < E.size(); i++)
    {
        u = E[i].u;
        v = E[i].v;
        pu = uf(u);
        pv = uf(v);
        if (pu != pv)
        {
            // printf("Add %d (%d) %d (%d)\n", u, Ic[u - 1], v, Ic[v - 1]);
            Pa[pu] = pv;
            Ans += E[i].w;
        }
    }
    return Ans;
}

컴파일 시 표준 에러 (stderr) 메시지

railroad.cpp: In function 'void update(int, int)':
railroad.cpp:23:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (; pos <= Ic.size(); pos += pos&-pos)
                ^
railroad.cpp: In function 'long long int plan_roller_coaster(std::vector<int>, std::vector<int>)':
railroad.cpp:71:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i = 1; i < Ic.size(); i++)
                   ^
railroad.cpp:87:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (i = 0; i < E.size(); i++)
                   ^

• Subtask 1: 11 / 11
• Subtask 2: 23 / 23
• Subtask 3: 30 / 30
• Subtask 4: 36 / 36