标签:ffffff 转化 sizeof wal queue str inf data this
先求出,终点到各个点的最短路,然后根据距离建立一个新图,转化为DAG动态规划问题。
#include<iostream> using namespace std; #include<cstdio> #include<cstring> #include<queue> #define MAXN 2010 #include<algorithm> typedef long long LL; struct teamdata{ LL d;LL point; bool operator<(const teamdata& pt)const{ return this->d>pt.d; } }; struct bian{ LL d,point; bool operator<(const bian &pt){ return this->d<pt.d; } }; LL n,m,k,l,s,t; LL pre[MAXN]; vector<LL> ansl; vector<bian> maps[MAXN]; const LL inf=0x7fffffff; LL d[MAXN]; priority_queue<teamdata> team; bool v[MAXN]; LL SPFA(LL s){ LL ans=-1; teamdata pt;pt.d=0;pt.point=s; memset(v,0,sizeof(v)); while(!team.empty()) team.pop(); team.push(pt);teamdata pd; for (LL i=0;i<=MAXN-1;i++) d[i]=inf,pre[i]=-1,v[i]=0; d[s]=0;v[s]=1; while(!team.empty()){ pt=team.top();team.pop(); //if (pt.d>d[pt.point]) continue; if (pt.point==t){ ans=pt.d;continue; } v[pt.point]=1; for (LL i=0;i<maps[pt.point].size();i++){ LL nb=maps[pt.point][i].point; if (v[nb]) continue; if (d[nb]>pt.d+maps[pt.point][i].d){ d[nb]=pt.d+maps[pt.point][i].d; pre[nb]=pt.point; pd.d=d[nb];pd.point=nb;team.push(pd); } } } return ans; } int aa[MAXN][MAXN]; LL f[MAXN]; bian fh[MAXN]; bool a[MAXN][MAXN]; LL dfs(int x){ if (f[x]>-1) return f[x]; LL ans=0; for (int i=1;i<=n;i++){ // if (i==x) continue; if (aa[x][i]) ans+=dfs(i); } f[x]=ans; return f[x]; } LL deal(){ if (scanf("%lld",&n)==EOF||n==0) return 0; scanf("%lld",&m); for (int i=0;i<=n;i++){ for (int j=0;j<=n;j++) { a[i][j]=0;f[i]=-1; } } for (LL i=0;i<=n;i++) maps[i].clear(); for (LL i=0;i<m;i++){ LL p,q,w; scanf("%lld%lld%lld",&p,&q,&w); bian pt; a[p][q]=a[q][p]=w; pt.point=q;pt.d=w; maps[p].push_back(pt); pt.point=p; maps[q].push_back(pt); } SPFA(2); memset(aa,0,sizeof(aa)); for (int i=1;i<=n;i++){ for (int j=1;j<=n;j++){ if (a[i][j]&&d[i]>d[j]) aa[i][j]=1; } } f[2]=1; printf("%lld\n",dfs(1)); } int main(){ while(deal()); return 0; }
Uva 10917 Walk Through the Forest
标签:ffffff 转化 sizeof wal queue str inf data this
原文地址:http://www.cnblogs.com/xfww/p/7620544.html