Time Limit: 1000MS | Memory Limit: 10000K | |
Total Submissions: 12622 | Accepted: 6773 |
Description
Your task is to design the network for the area, so that there is a connection (direct or indirect) between every two points (i.e., all the points are interconnected, but not necessarily by a direct cable), and that the total length of the used cable is minimal.
Input
The maximal number of points is 50. The maximal length of a given route is 100. The number of possible routes is unlimited. The nodes are identified with integers between 1 and P (inclusive). The routes between two points i and j may be given as i j or as j i.
Output
Sample Input
1 0 2 3 1 2 37 2 1 17 1 2 68 3 7 1 2 19 2 3 11 3 1 7 1 3 5 2 3 89 3 1 91 1 2 32 5 7 1 2 5 2 3 7 2 4 8 4 5 11 3 5 10 1 5 6 4 2 12 0
Sample Output
0 17 16 26
最小生成樹模板題
入門:http://www.cnblogs.com/biyeymyhjob/archive/2012/07/30/2615542.html
kruskal
#include <iostream>
#include <algorithm>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <string>
#include <set>
#include <map>
#include <stack>
#include <vector>
#include <list>
#include <bitset>
#include <queue>
using namespace std;
#define mem(a, b) memset(a, b, sizeof(a))
#define ll long long
#define debug() puts("FFF~!!!!!");
const int inf = 0x3f3f3f3f;
const int maxn = 1300;
int n, m;
int cnt, p[maxn];
struct Edge {
int u, v, cost;
}edge[maxn];
bool cmp(Edge a, Edge b) {
return a.cost < b.cost;
}
int find(int x) {
return p[x] = x == p[x] ? x : find(p[x]);
}
int kruskal() {
int ans = 0;
for (int i = 0; i <= n; i ++) {
p[i] = i;
}
sort(edge, edge + m, cmp);
for (int i = 0; i < m; i ++) {
int x = find(edge[i].u);
int y = find(edge[i].v);
if (x != y) {
p[x] = y;
ans += edge[i].cost;
}
}
return ans;
}
int main()
{
while (cin >> n && n) {
cin >> m;
for (int i = 0; i < m; i ++) {
cin >> edge[i].u >> edge[i].v >> edge[i].cost;
}
int ans = kruskal();
cout << ans << endl;
}
}