題目簡介
好像就是直接求最小生成樹啊……
說明
就是記錄一下寫得比較簡潔的Prim算法而已。
#include <bits/stdc++.h>
using namespace std;
const int maxn = 105;
const int INF = 0x3f3f3f3f;
int mp[maxn][maxn], dis[maxn], vis[maxn], n, sum;
inline int prim()
{
memset(vis, 0, sizeof vis);
memset(dis, INF, sizeof dis);
sum = dis[1] = 0;
for (;;)
{
int u = -1, v, mincost = INF;
for (int i = 1; i <= n; ++i)
if (dis[i] < mincost && !vis[i])
{
mincost = dis[i];
u = i;
}
if (u == -1) break;
vis[u] = 1;
sum += dis[u];
for (v = 1; v <= n; ++v)
if (dis[v] > mp[u][v]) dis[v] = mp[u][v];
}
return sum;
}
int main()
{
while (cin >> n)
{
memset(mp, INF, sizeof mp);
for (int i = 1; i <= n; ++i)
for (int j = 1; j <= n; ++j)
scanf("%d", &mp[i][j]);
printf("%d\n", prim());
}
return 0;
}