Pagini recente » Cod sursa (job #1699621) | Cod sursa (job #438860) | Cod sursa (job #2498675) | Cod sursa (job #2256164) | Cod sursa (job #1021659)
#include <cstring>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <set>
#include <iostream>
#include <queue>
using namespace std;
struct edge {
int from, to, cost;
};
struct edge_cmp {
bool operator() (const edge& e1, const edge& e2) {
return e1.cost > e2.cost;
}
};
int main() {
freopen("apm.in", "r", stdin);
freopen("apm.out", "w", stdout);
int n, m;
scanf("%d %d", &n, &m);
vector<edge> nodes[n + 1];
for (int i = 0; i < m; i++) {
int from, to, cost;
scanf("%d %d %d", &from, &to, &cost);
edge e;
e.from = from;
e.to = to;
e.cost = cost;
nodes[from].push_back(e);
edge e2;
e2.from = to;
e2.to = from;
e2.cost = cost;
nodes[to].push_back(e2);
}
priority_queue<edge, vector<edge>, edge_cmp> heap;
int n_seen = 1;
int min_cost = 0;
vector<edge> mstree;
vector<edge>::iterator it;
for (it = nodes[1].begin(); it != nodes[1].end();it++) {
heap.push(*it);
// cout << "Pushed " << it->cost << endl;
}
int seen[n + 1];
memset(seen, 0, sizeof(int) * (n + 1));
seen[1] = 1;
while (n_seen < n) {
/*cout << endl;
cout << "min_cost" << min_cost << endl;
cout << "Seen " << seen << endl;
cout << "Heap.top" << heap.top().cost << endl;*/
edge e = heap.top(); heap.pop();
if (seen[e.to] == 1 && seen[e.from] == 1)
continue;
seen[e.to] = 1;
mstree.push_back(e);
min_cost += e.cost;
/* cout << "e.to = " << e.to << endl;
cout << "e.to.size()" << nodes[e.to].size() << endl;*/
for (it = nodes[e.to].begin(); it != nodes[e.to].end(); it++) {
heap.push(*it);
// cout << "Adding " << it->cost << endl;
}
n_seen++;
}
printf("%d\n", min_cost);
printf("%d\n", mstree.size());
for (it = mstree.begin(); it != mstree.end(); it++) {
printf("%d %d \n", it->from, it->to);
}
return 0;
}