1087 All Roads Lead to Rome [dj]

#include<iostream>
#include<vector>
#include<queue>
#include<stack>
#include<string>
#include<math.h>
#include<algorithm>
#include<map>
#include<cstring>
#include<set>
using namespace std;
const int maxn = 1001;
const int inf = 1000000001;
int n, m, k, ds, st;
int weight[maxn];
int d[maxn], num[maxn], w[maxn], Count[maxn], pre[maxn];
int G[maxn][maxn];
bool vis[maxn];
map<string, int>cityToindex;
map<int, string>indexTocity;

void dj(int s)
{
	fill(d, d + maxn, inf);
	memset(w, 0, sizeof(w));
	memset(num, 0, sizeof(num));
	memset(Count, 0, sizeof(Count));
	d[s] = 0;
	num[s] = 1;
	for (int i = 0; i < n; i++)
	{
		int u = -1, min = inf;
		for (int j = 0; j < n; j++)
		{
			if (vis[j] == false && d[j] < min)
			{
				u = j;
				min = d[j];
			}
		}
		if (u == -1)
			return;
		vis[u] = true;
		for (int v = 0; v < n; v++)
		{
			if (vis[v] == false)
			{
				if (d[u] + G[u][v] < d[v])
				{
					d[v] = d[u] + G[u][v];
					w[v] = w[u] + weight[v];
					num[v] = num[u];
					Count[v] = Count[u] + 1;
					pre[v] = u;
				}
				else if (d[u] + G[u][v] == d[v])
				{
					num[v] += num[u];
					if (w[u] + weight[v] > w[v])
					{
						w[v] = w[u] + weight[v];
						Count[v] = Count[u] + 1;
						pre[v] = u;
					}
					else if (w[u] + weight[v] == w[v])
					{
						double uAvg = 1.0 * (w[u] + weight[v]) / (Count[u] + 1);
						double vAvg = 1.0 * w[v] / Count[v];
						if (uAvg > vAvg)
						{
							Count[v] = Count[u] + 1;
							pre[v] = u;
						}
					}
				}
			}
		}
	}
}

void print(int v)
{
	if (v == 0)
	{
		cout << indexTocity[v];
		return;
	}
	print(pre[v]);
	cout << "->" << indexTocity[v];
}

int main()
{
	string start, city1, city2;
	cin >> n >> m >> start;
	cityToindex[start] = 0;
	indexTocity[0] = start;
	for (int i = 1; i < n; i++)
	{
		cin >> city1 >> weight[i];
		cityToindex[city1] = i;
		indexTocity[i] = city1;
	}
	fill(G[0], G[0] + maxn * maxn, inf);
	for (int i = 0; i < m; i++)
	{
		cin >> city1 >> city2;
		int c1 = cityToindex[city1], c2 = cityToindex[city2];
		cin >> G[c1][c2];
		G[c2][c1] = G[c1][c2];
	}
	dj(0);
	int rom = cityToindex["ROM"];
	cout << num[rom] << " " << d[rom] << " " << w[rom] << " " << w[rom] / Count[rom] << endl;
	print(rom);
}