Prim minimum spanning tree algorithm problem poj2485

Start to write runtime error using Kruskal algorithm

#include <cstdio> #include <queue> #include <set>using namespace Std;int a[2510][25100];struct weight    {int A, B;    int value;    BOOL operator < (const weight & RHS) Const {return value < Rhs.value;    } BOOL operator > (const weight & RHS) Const {return value > rhs.value;    }};int sett[251000];int find2 (int x) {while (x! = Sett[x]) x=sett[x]; return x;}    void Merge2 (int a,int b) {if (a > B) sett[a]=b; else Sett[b]=a;}    int main () {int t;    scanf ("%d", &t);        while (t--) {priority_queue<weight, vector<weight>, greater<weight> > PQ;        int n;        scanf ("%d", &n);        for (int i=0;i<n;i++) sett[i]=i;                for (int i=0;i<n;i++) for (int j=0;j<n;j++) {int x;                scanf ("%d", &x);                if (x = = 0) x = 65537;                Weight route;                Route.a=i;                Route.b=j; Route.value=X            Pq.push (route);        } set<int> drop;//printf ("size=%d n=%d\n", Drop.size (), n);            while (Drop.size ()! = n-1) {//printf ("size=%d n=%d\n", Drop.size (), n);            Weight mi = pq.top ();            Pq.pop ();            int FX =find2 (MI.A);            int fy =find2 (MI.B);                if (fx!=fy) {Drop.insert (mi.value);            Merge2 (FX,FY); }}//printf ("size%d\n", Drop.size ());//For (Set<int>::iterator it=drop.begin (); It!=drop.end (); it++) {//printf ("dsa\n");//printf ("%d", *it);/} Set<int>::iterator it = drop.        End ();        it--;    printf ("%d\n", *it); } return 0;} /*140 1 2 31 0 2 32 2 0 33 3 3 0-1073741819-1073741819*/

Then write the prim algorithm

#include <cstdio> #include <algorithm> #include <cstring>using namespace Std;int cost[510][510];int Mincost[510];bool used[510];int N;int Prim () {    memset (used,false,sizeof (used));    memset (mincost,65537,sizeof (Mincost));    int maxres=0;    mincost[0]=0;    while (true) {        int v=-1;        for (int i=0;i<n;i++)            if (!used[i] && (v==-1 | | mincost[i]<mincost[v])  ) v=i;        if (v = =-1) break;        Used[v]=true;        if (Mincost[v] >maxres) maxres=mincost[v];        for (int i=0;i<n;i++)            mincost[i] = min (Mincost[i], cost[v][i]);    }    return maxres;} int main () {    int cases;    scanf ("%d", &cases);    while (cases--) {            scanf ("%d", &n);    for (int i=0;i<n;i++) for        (int j=0;j<n;j++)    {        int x;        scanf ("%d", &cost[i][j]);        if (cost[i][j]== 0) cost[i][j] = 65537;    }    printf ("%d\n", Prim ());    }    return 0;}

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Prim minimum spanning tree algorithm problem poj2485