Submission #6617

#	Time	Username	Problem	Language	Result	Execution time	Memory
6617		mrcamel	비용 (KOI11_cost)	C++98	22.80 / 24	156 ms	4412 KiB

cost

#include <iostream>
#include <algorithm>
using namespace std;

#define in cin
#define out cout
#define DIV 1000000000
#define int64 long long int

struct LL
{
    int s, e, w;
}L[100001];

struct VV
{
    int subN;
    int parent;
}Vtx[100001];

int cmp(const LL &a, const LL &b)
{
    return a.w > b.w;
}

int find(int idx)
{
	if(idx != Vtx[idx].parent) Vtx[idx].parent = find(Vtx[idx].parent);
	return Vtx[idx].parent;
}

int64 sum[100001]; //합

int main()
{
    int n, k;
    in >> n >> k; //정점, 간선

    for(int i=0; i<k; i++)
        in >> L[i].s >> L[i].e >> L[i].w;

    sort(L, L+k, cmp);

    for(int i=1; i<=n; i++)
    {
        Vtx[i].parent = i;
        Vtx[i].subN = 1;
    }

    for(int i=0; i<k; i++) {
        if(i != 0) sum[i] = sum[i-1] + L[k-i-1].w;
        else sum[i] = L[k-1].w;
    } reverse(sum, sum+k);

    int64 res = 0;
    for(int i=0; i<k; i++)
    {
        int v1 = L[i].s;
        int v2 = L[i].e;

        int p1 = find(v1);
        int p2 = find(v2);

        if(p1 != p2)
        {
            res += (Vtx[p1].subN * Vtx[p2].subN * sum[i]);
            res %= DIV;

            Vtx[p1].subN += Vtx[p2].subN;
            Vtx[p2].parent = p1;
        }
    }

    out << res << endl;

    return 0;
}

• Subtask 1: 4.8 / 4.8
• Subtask 2: 7.2 / 7.2
• Subtask 3: 10.8 / 12