hdu1102 Constructing Roads

先把已知路段的距离设为0，然后prim

code

/*ID: yueqiqPROG: numtriLANG: C++*/#include <set>#include <map>#include <ctime>#include <queue>#include <cmath>#include <stack>#include <limits>#include <vector>#include <bitset>#include <string>#include <cstdio>#include <cstring>#include <fstream>#include <string.h>#include <iostream>#include <algorithm>#define Si set<int>#define LL long long#define pb push_back#define PS printf(" ")#define Vi vector<int>#define LN printf("\n")#define lson l,m,rt << 1#define rson m+1,r,rt<<1|1#define SD(a) scanf("%d",&a)#define PD(a) printf("%d",a)#define SET(a,b) memset(a,b,sizeof(a))#define FF(i,a) for(int i(0);i<(a);i++)#define FD(i,a) for(int i(a);i>=(1);i--)#define FOR(i,a,b) for(int i(a);i<=(b);i++)#define FOD(i,a,b) for(int i(a);i>=(b);i--)#define readf freopen("input.txt","r",stdin)#define writef freopen("output.txt","w",stdout)const int maxn = 101;const int INF = 1111;const int dx[]={0,1,0,-1};const int dy[]={1,0,-1,0};const double pi = acos(-1.0);const double eps= 1e-7;using namespace std;int N,M;int edge[maxn][maxn];int dis[maxn];bool vis[maxn];int prim(){    SET(vis,false);    int s=1;    FOR(i,1,N) dis[i]=edge[1][i];    vis[s]=true;    int minn;    int ans=0;    FOR(i,1,N-1){        minn=INF;        FOR(j,1,N){            if(!vis[j] && dis[j]<minn){                minn=dis[j];                s=j;            }        }        vis[s]=true;        ans+=minn;        FOR(j,1,N){            if(!vis[j] && dis[j]>edge[s][j])                dis[j]=edge[s][j];        }    }    return ans;}int main(){    while(~scanf("%d",&N)){        FOR(i,1,N) FOR(j,1,N) edge[i][j]=INF;        FOR(i,1,N) FOR(j,1,N){            SD(edge[i][j]);        }        SD(M);        int a,b;        FOR(i,1,M){            SD(a);SD(b);            edge[a][b]=edge[b][a]=0;        }        PD(prim());LN;    }    return 0;}