Prim 算法， hdu 1102 Constructing Roads

/*
* m.cpp
*
*  Created on: 2010-5-3
*      Author: Administrator
*/
#include <iostream>
//#include <iostream.h>
#include <queue>
#include <string>
#include <utility>
#include <vector>
#include <functional>
#include <cmath>
#include <limits>
using namespace std;
typedef pair<int, int> vetex;
int prim(int map[][101], int n)
{
int max = 0;
int visit[101], distance[101];
for (int i = 0; i < 101; i++)
{
visit[i] = false;
distance[i] = 2000;
}
distance[1] = 0;
priority_queue<vetex, vector<vetex>, greater<vetex> > q;
q.push(vetex(0, 1));
while (!q.empty())
{
int u = q.top().second;
visit[u] = true;
q.pop();
for (int i = 1; i <= n; i++)
{
if (!visit[i] && map[u][i] < distance[i])
{
distance[i] = map[u][i];
q.push(vetex(map[u][i], i));
}
}
}
for (int i = 1; i <= n; i++)
{
max += distance[i];
}
return max;
}
int main()
{
//freopen("in.txt", "r", stdin);
int n;
int map[101][101];
while (scanf("%d", &n) != EOF)
{
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= n; j++)
{
scanf("%d", &map[i][j]);
}
}
int t;
int a, b;
scanf("%d", &t);
for (int i = 0; i < t; i++)
{
scanf("%d %d", &a, &b);
map[a] = 0;
map[b][a] = 0;
}
cout<<prim(map, n)<<endl;
}
return 0;
}

/*
* m.cpp
*
*  Created on: 2010-5-3
*      Author: Administrator
*/
#include <iostream>
#include <queue>
#include <string>
#include <utility>
#include <vector>
#include <functional>
using namespace std;
struct node
{
int distance;
int visitp; //最小生成树，已经访问过的点
int nextp; //最小生成树外面，与树连接且未访问过的点
//保存两点之间已经访问过的点， 和未访问过的点， 以及两点距离。
friend bool operator>(const node & a, const node & b)
{
return a.distance > b.distance;
}
friend bool operator<(const node & a, const node & b)
{
return a.distance < b.distance;
}
node(const int &a, const int &b, const int &c)
{
distance = a;
visitp = b;
nextp = c;
}
};
int prim(int map[][101], int n)
{
int max = 0;
int visit[101];
for (int i = 0; i < 101; i++)
{
visit[i] = false;
}
priority_queue<node, vector<node>, greater<node> > q;
q.push(node(0, 1, 1));
while (!q.empty())
{
int u = q.top().nextp;
if (!visit[u])
{
max += map[q.top().visitp][u];
visit[u] = true;
}
q.pop();
for (int i = 1; i <= n; i++)
{
if (!visit[i])
{
q.push(node(map[u][i], u, i));
}
}
}
return max;
}
int main()
{
//freopen("in.txt", "r", stdin);
int n;
int map[101][101];
while (scanf("%d", &n) != EOF)
{
for (int i = 1; i <= n; i++)
{
for (int j = 1; j <= n; j++)
{
scanf("%d", &map[i][j]);
}
}
int t;
int a, b;
scanf("%d", &t);
for (int i = 0; i < t; i++)
{
scanf("%d %d", &a, &b);
map[a][b] = 0;
map[b][a] = 0;
}
cout<<prim(map, n)<<endl;
}
return 0;
}