标签:blog io os for sp div on log bs
借bzoj1624练了一下模板(虽然正解只是floyd)
spfa:
#include <cstdio> #include <cstring> #include <algorithm> #include <iostream> #include <vector> #include <queue> using namespace std; const int INF=100001; const int maxm=10001,maxn=101; int n,m,x,y,w; long long ans=0; int a[maxm]; int dist[maxn]; bool vis[maxn]; struct edge{ int to,w; edge(int _to,int _w){to=_to;w=_w;} }; vector <edge> g[maxm]; void spfa(int x){ queue<int> q; memset(dist,63,sizeof(dist)); memset(vis,false,sizeof(vis)); dist[x]=0; vis[x]=1; q.push(x); while(!q.empty()){ int u=q.front(); q.pop(); vis[u]=0; int l=g[u].size(); for(int i=0;i<l;i++){ int v=g[u][i].to; if(dist[v]>dist[u]+g[u][i].w){ dist[v]=dist[u]+g[u][i].w; if(!vis[v]){ vis[v]=1;q.push(v); } } } } } int main(){ freopen("data.in","r",stdin); freopen("text.out","w",stdout); //freopen("data.txt","r",stdin); scanf("%d%d",&n,&m); for(int i=1;i<=m;i++) scanf("%d",&a[i]); for(int i=1;i<=n;i++) for(int j=1;j<=n;j++){ scanf("%d",&w); if(i!=j) g[i].push_back(edge(j,w)); } for(int i=1;i<m;i++){ spfa(a[i]); ans+=dist[a[i+1]]; } cout<<ans; return 0; }
dijkstra+priority_queue:
#include <cstdio> #include <cstring> #include <algorithm> #include <iostream> #include <vector> #include <queue> using namespace std; const int INF=100001; const int maxm=10001,maxn=101; int n,m,x,y,w; long long ans=0; int a[maxm]; int dist[maxn]; struct edge{ int to,w; edge(int _to,int _w){to=_to;w=_w;} }; vector <edge> g[maxm]; typedef pair<int,int> P; void dijkstra(int x){ priority_queue< P , vector <P> , greater<P> > q; memset(dist,63,sizeof(dist)); dist[x]=0; q.push(P(0,x)); while(!q.empty()){ P u=q.top(); int x=u.second; q.pop(); if(dist[x]<u.first) continue; int l=g[x].size(); for(int i=0;i<l;i++){ int v=g[x][i].to; if(dist[v]>dist[x]+g[x][i].w){ dist[v]=dist[x]+g[x][i].w; q.push(P(dist[v],v)); } } } } int main(){ freopen("danger.in","r",stdin); freopen("danger.out","w",stdout); //freopen("data.txt","r",stdin); scanf("%d%d",&n,&m); for(int i=1;i<=m;i++) scanf("%d",&a[i]); for(int i=1;i<=n;i++) for(int j=1;j<=n;j++){ scanf("%d",&w); if(i!=j) g[i].push_back(edge(j,w)); } for(int i=1;i<m;i++){ dijkstra(a[i]); ans+=dist[a[i+1]]; } cout<<ans; return 0; }
floyd:
#include<cstdio> #include<iostream> #include<algorithm> #include<cmath> #include<cstring> #include<string> #include<queue> #include<stack> #include<vector> using namespace std; int n,m,i,j,k,ans,f[102][102],a[10002]; int main(){ cin>>n>>m; for(i=1;i<=m;i++)scanf("%d",&a[i]); for(i=1;i<=n;i++) for(j=1;j<=n;j++) scanf("%d",&f[i][j]); for(k=1;k<=n;k++) for(i=1;i<=n;i++) for(j=1;j<=n;j++) f[i][j]=min(f[i][j],f[i][k]+f[k][j]); for(i=2;i<=m;i++)ans+=f[a[i-1]][a[i]]; cout<<ans; return 0; }
最短路模板[spfa][dijkstra+堆优化][floyd]
标签:blog io os for sp div on log bs
原文地址:http://www.cnblogs.com/polebug/p/4072713.html