woj 1050 最小生成树

kruskal算法:

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
#define MAXV 100//后面都会用到
#define MAXSIZE (100*100)
#define INF 100000//INF表示正无穷
struct MGraph
{
    int edges[MAXV][MAXV];//邻接矩阵的边数组
    int n;//顶点数,弧度;
};
MGraph g;
int sum;
//并查集
int Father[MAXV]; // Father[i] 表示 i 的父节点
int FindSet(int x)
{
    while (x != Father[x]) x = Father[x];
    return x;
}
//边
struct Edge
{
    int p1,p2;
    int val;
};
bool cmp(Edge a,Edge b)
{
    return a.val < b.val;//按照边从小到大排序
}
void Kruskal(MGraph g)
{
    Edge e[MAXSIZE];//边数组
    int i,j,k=0;
    //对边进行排序
    for(i=0;i<g.n;i++)
    for(j=0;j<g.n;j++)
       if(g.edges[i][j]!=0 && g.edges[i][j]!=INF)
       {
           e[k].p1=i; e[k].p2=j; e[k].val=g.edges[i][j];
           k++;
       }
    sort(e,e+k,cmp);
    //初始化并查集
    for(i=0;i<g.n;i++) Father[i]=i;
    //处理
    k=1; j=1;
    while(k<g.n)
    {
        int f1=FindSet(e[j].p1), f2=FindSet(e[j].p2);
        if(f1!=f2)
        {
            k++; sum +=e[j].val;
            Father[f1]=f2;//并查集合并
        }
        j++;
    }
}
int main()
{
    freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
    int ncase,i,j;
    cin>>ncase;
    while(ncase--)
    {
        cin>>g.n;
        for(i=0;i<g.n;i++)
        for(j=0;j<g.n;j++)  cin>>g.edges[i][j];
        sum=0;
        Kruskal(g);
        cout<<sum<<endl;
    }
    return 0;
}

prime算法:

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <cmath>
using namespace std;
#define MAXV 100//后面都会用到
#define INF 100000//INF表示正无穷
typedef struct
{
    int edges[MAXV][MAXV];//邻接矩阵的边数组
    int n,e;//顶点数,弧度;
}MGraph;
MGraph g;
int sum;
void Prime(MGraph g,int v)
{
    int lowcost[MAXV],closest[MAXV];
    int min,i,j,k;
    for(i=0;i<g.n;i++)//给lowcost[]和closest赋初值
    {
        lowcost[i]=g.edges[v][i];
        closest[i]=v;
    }
    for(i=1;i<g.n;i++)//找出n-1个顶点
    {
        min=INF;
        for(j=0;j<g.n;j++)//在V-U中找出离U最近的顶点k
            if(lowcost[j]!=0 && lowcost[j]<min)
            {
                min=lowcost[j]; k=j;//k记录最近顶点的编号
            }
        sum +=min;
        //cout<<k<<" "<<sum<<endl;
        lowcost[k]=0;//标记k已经加入U
        for(j=0;j<g.n;j++)//修改数组lowcost和closest
            if(g.edges[k][j]!=0 && g.edges[k][j]<lowcost[j])
            {
                lowcost[j]=g.edges[k][j];  closest[j]=k;
            }
    }
}
int main()
{
    freopen("in.txt", "r", stdin);
    //freopen("out.txt", "w", stdout);
    int ncase,i,j;
    cin>>ncase;
    while(ncase--)
    {
        cin>>g.n;
        for(i=0;i<g.n;i++)
        for(j=0;j<g.n;j++)  cin>>g.edges[i][j];
        sum=0;
        Prime(g,0);
        cout<<sum<<endl;
    }
    return 0;
}