poj 1251

代码

#include < iostream >
using namespace std;
#define N 27
#define M 27
#define INF 111
int dist[N];
int P[M][M]; // 初始值为INF;
int n; // n个村庄;
int used[N];
int total;
void prim();

int main()
{
char v;
char tmp;
int money;
int num;
cin >> n;
while (n)
{
total = 0 ;
for ( int m = 0 ;m < N;m ++ )
{
dist[m] = INF;
used[m] = 0 ;
}
for ( int j = 0 ;j < M;j ++ )
for ( int k = 0 ;k < M;k ++ )
P[j][k] = INF;
int i = 0 ;
for (i = 0 ;i < n - 1 ;i ++ )
{ cin >> v;
cin >> num;
while (num -- ){
cin >> tmp;
cin >> money;
P[v - ' A ' ][tmp - ' A ' ] = P[tmp - ' A ' ][v - ' A ' ] = money;
}
}

prim();

cout << total << endl;
cin >> n;

}

}


void prim() // 从第o点开始;
{
for ( int i = 0 ;i < n;i ++ )
dist[i] = P[ 0 ][i];
used[ 0 ] = 1 ;
int x;
for (x = 0 ;x < n;x ++ ){


int min = INF; int f =- 1 ;
for ( int i = 0 ;i < n;i ++ )
if ( ! used[i] && dist[i] < min)
{
min = dist[i];
f = i;
}
if (f ==- 1 )
break ;
else {
used[f] = 1 ;
total += dist[f];
}

for ( int z = 0 ;z < n;z ++ ){
if ( ! used[z] && P[f][z] < dist[z])
{
dist[z] = P[f][z];
}
}
}
}

 

很简单  很基础的最小生成树   既然ac了   就把代码贴出来了 :

 

 

 

转载于:https://www.cnblogs.com/anotherday/archive/2010/11/28/1890588.html